Programs & Examples On #Pinning

How to get Django and ReactJS to work together?

I know this is a couple of years late, but I'm putting it out there for the next person on this journey.

GraphQL has been helpful and way easier compared to DjangoRESTFramework. It is also more flexible in terms of the responses you get. You get what you ask for and don't have to filter through the response to get what you want.

You can use Graphene Django on the server side and React+Apollo/Relay... You can look into it as that is not your question.

How to pass data using NotificationCenter in swift 3.0 and NSNotificationCenter in swift 2.0?

Swift 2.0

Pass info using userInfo which is a optional Dictionary of type [NSObject : AnyObject]?

  let imageDataDict:[String: UIImage] = ["image": image]

  // Post a notification
  NSNotificationCenter.defaultCenter().postNotificationName(notificationName, object: nil, userInfo: imageDataDict)

 // Register to receive notification in your class
 NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(self.showSpinningWheel(_:)), name: notificationName, object: nil)

 // handle notification
 func showSpinningWheel(notification: NSNotification) { 

  if let image = notification.userInfo?["image"] as? UIImage {
  // do something with your image   
  }
 }

Swift 3.0 version and above

The userInfo now takes [AnyHashable:Any]? as an argument, which we provide as a dictionary literal in Swift

  let imageDataDict:[String: UIImage] = ["image": image]

  // post a notification
  NotificationCenter.default.post(name: NSNotification.Name(rawValue: "notificationName"), object: nil, userInfo: imageDataDict) 
  // `default` is now a property, not a method call

 // Register to receive notification in your class
 NotificationCenter.default.addObserver(self, selector: #selector(self.showSpinningWheel(_:)), name: NSNotification.Name(rawValue: "notificationName"), object: nil)

 // handle notification
 // For swift 4.0 and above put @objc attribute in front of function Definition  
 func showSpinningWheel(_ notification: NSNotification) {

  if let image = notification.userInfo?["image"] as? UIImage {
  // do something with your image   
  }
 }

NOTE: Notification “names” are no longer strings, but are of type Notification.Name, hence why we are using NSNotification.Name(rawValue:"notificationName") and we can extend Notification.Name with our own custom notifications.

extension Notification.Name {
static let myNotification = Notification.Name("myNotification")
}

// and post notification like this
NotificationCenter.default.post(name: .myNotification, object: nil)

Spin or rotate an image on hover

It's very simple.

  1. You add an image.
  2. You create a css property to this image.

    img { transition: all 0.3s ease-in-out 0s; }
    
  3. You add an animation like that:

    img:hover
    {
        cursor: default;
        transform: rotate(360deg);
        transition: all 0.3s ease-in-out 0s;
    }
    

How can I use LTRIM/RTRIM to search and replace leading/trailing spaces?

SELECT RTRIM(' Author ') AS Name;

Output will be without any trailing spaces.

Name —————— ‘ Author’

ProgressDialog spinning circle

I was using View.INVISIBLE and View.VISIBLE and the ProgressBar would slowly flash instead of constantly being visible, switched to View.GONE and View.VISIBLE and it works perfectly

support FragmentPagerAdapter holds reference to old fragments

I solved the problem by saving the fragments in SparceArray:

public abstract class SaveFragmentsPagerAdapter extends FragmentPagerAdapter {

    SparseArray<Fragment> fragments = new SparseArray<>();

    public SaveFragmentsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        Fragment fragment = (Fragment) super.instantiateItem(container, position);
        fragments.append(position, fragment);
        return fragment;
    }

    @Nullable
    public Fragment getFragmentByPosition(int position){
        return fragments.get(position);
    }

}

How do I tell Python to convert integers into words

This does the job without any library. Used recursion and it is Indian style. -- Ravi.

def spellNumber(no):
    # str(no) will result in  56.9 for 56.90 so we used the method which is given below.
    strNo = "%.2f" %no
    n = strNo.split(".")
    rs = numberToText(int(n[0])).strip()
    ps =""
    if(len(n)>=2):
        ps = numberToText(int(n[1])).strip()
        rs = "" + ps+ " paise"  if(rs.strip()=="") else  (rs + " and " + ps+ " paise").strip()
    return rs
print(spellNumber(0.67))
print(spellNumber(5858.099))
print(spellNumber(5083754857380.50))    

def numberToText(no):
    ones = " ,one,two,three,four,five,six,seven,eight,nine,ten,eleven,tweleve,thirteen,fourteen,fifteen,sixteen,seventeen,eighteen,nineteen,twenty".split(',')
    tens = "ten,twenty,thirty,fourty,fifty,sixty,seventy,eighty,ninety".split(',')
    text = ""
    if len(str(no))<=2:
        if(no<20):
            text = ones[no]
        else:
            text = tens[no//10-1] +" " + ones[(no %10)]
    elif len(str(no))==3:
        text = ones[no//100] +" hundred " + numberToText(no- ((no//100)* 100))
    elif len(str(no))<=5:
        text = numberToText(no//1000) +" thousand " + numberToText(no- ((no//1000)* 1000))
    elif len(str(no))<=7:
        text = numberToText(no//100000) +" lakh " + numberToText(no- ((no//100000)* 100000))
    else:
        text = numberToText(no//10000000) +" crores " + numberToText(no- ((no//10000000)* 10000000))
    return text

How can I get a list of Git branches, ordered by most recent commit?

The accepted command-line answer rocks, but if you want something prettier, like a GUI, and your origin === "github".

You can click "Branches" in the repository. Or hit the URL directly: https://github.com/ORGANIZATION_NAME/REPO_NAME/branches

How to use type: "POST" in jsonp ajax call

You can't POST using JSONP...it simply doesn't work that way, it creates a <script> element to fetch data...which has to be a GET request. There's not much you can do besides posting to your own domain as a proxy which posts to the other...but user's not going to be able to do this directly and see a response though.

How to display a "busy" indicator with jQuery?

The jQuery documentation recommends doing something like the following:

$( document ).ajaxStart(function() {
  $( "#loading" ).show();
}).ajaxStop(function() {
  $( "#loading" ).hide();
});

Where #loading is the element with your busy indicator in it.

References:

Facebook Architecture

Facebook is using LAMP structure. Facebook’s back-end services are written in a variety of different programming languages including C++, Java, Python, and Erlang and they are used according to requirement. With LAMP Facebook uses some technologies ,to support large number of requests, like

  1. Memcache - It is a memory caching system that is used to speed up dynamic database-driven websites (like Facebook) by caching data and objects in RAM to reduce reading time. Memcache is Facebook’s primary form of caching and helps alleviate the database load. Having a caching system allows Facebook to be as fast as it is at recalling your data.

  2. Thrift (protocol) - It is a lightweight remote procedure call framework for scalable cross-language services development. Thrift supports C++, PHP, Python, Perl, Java, Ruby, Erlang, and others.

  3. Cassandra (database) - It is a database management system designed to handle large amounts of data spread out across many servers.

  4. HipHop for PHP - It is a source code transformer for PHP script code and was created to save server resources. HipHop transforms PHP source code into optimized C++. After doing this, it uses g++ to compile it to machine code.

If we go into more detail, then answer to this question go longer. We can understand more from following posts:

  1. How Does Facebook Work?
  2. Data Management, Facebook-style
  3. Facebook database design?
  4. Facebook wall's database structure
  5. Facebook "like" data structure

How to create loading dialogs in Android?

It's a ProgressDialog, with setIndeterminate(true).

From http://developer.android.com/guide/topics/ui/dialogs.html#ProgressDialog

ProgressDialog dialog = ProgressDialog.show(MyActivity.this, "", 
                    "Loading. Please wait...", true);

An indeterminate progress bar doesn't actually show a bar, it shows a spinning activity circle thing. I'm sure you know what I mean :)

How can I create a "Please Wait, Loading..." animation using jQuery?

You could do this various different ways. It could be a subtle as a small status on the page saying "Loading...", or as loud as an entire element graying out the page while the new data is loading. The approach I'm taking below will show you how to accomplish both methods.

The Setup

Let's start by getting us a nice "loading" animation from http://ajaxload.info I'll be using enter image description here

Let's create an element that we can show/hide anytime we're making an ajax request:

<div class="modal"><!-- Place at bottom of page --></div>

The CSS

Next let's give it some flair:

/* Start by setting display:none to make this hidden.
   Then we position it in relation to the viewport window
   with position:fixed. Width, height, top and left speak
   for themselves. Background we set to 80% white with
   our animation centered, and no-repeating */
.modal {
    display:    none;
    position:   fixed;
    z-index:    1000;
    top:        0;
    left:       0;
    height:     100%;
    width:      100%;
    background: rgba( 255, 255, 255, .8 ) 
                url('http://i.stack.imgur.com/FhHRx.gif') 
                50% 50% 
                no-repeat;
}

/* When the body has the loading class, we turn
   the scrollbar off with overflow:hidden */
body.loading .modal {
    overflow: hidden;   
}

/* Anytime the body has the loading class, our
   modal element will be visible */
body.loading .modal {
    display: block;
}

And finally, the jQuery

Alright, on to the jQuery. This next part is actually really simple:

$body = $("body");

$(document).on({
    ajaxStart: function() { $body.addClass("loading");    },
     ajaxStop: function() { $body.removeClass("loading"); }    
});

That's it! We're attaching some events to the body element anytime the ajaxStart or ajaxStop events are fired. When an ajax event starts, we add the "loading" class to the body. and when events are done, we remove the "loading" class from the body.

See it in action: http://jsfiddle.net/VpDUG/4952/

How can I display a JavaScript object?

Use native JSON.stringify method. Works with nested objects and all major browsers support this method.

str = JSON.stringify(obj);
str = JSON.stringify(obj, null, 4); // (Optional) beautiful indented output.
console.log(str); // Logs output to dev tools console.
alert(str); // Displays output using window.alert()

Link to Mozilla API Reference and other examples.

obj = JSON.parse(str); // Reverses above operation (Just in case if needed.)

Use a custom JSON.stringify replacer if you encounter this Javascript error

"Uncaught TypeError: Converting circular structure to JSON"

Update UI from Thread in Android

Use the AsyncTask class (instead of Runnable). It has a method called onProgressUpdate which can affect the UI (it's invoked in the UI thread).

How to encode text to base64 in python

Use the below code:

import base64

#Taking input through the terminal.
welcomeInput= raw_input("Enter 1 to convert String to Base64, 2 to convert Base64 to String: ") 

if(int(welcomeInput)==1 or int(welcomeInput)==2):
    #Code to Convert String to Base 64.
    if int(welcomeInput)==1:
        inputString= raw_input("Enter the String to be converted to Base64:") 
        base64Value = base64.b64encode(inputString.encode())
        print "Base64 Value = " + base64Value
    #Code to Convert Base 64 to String.
    elif int(welcomeInput)==2:
        inputString= raw_input("Enter the Base64 value to be converted to String:") 
        stringValue = base64.b64decode(inputString).decode('utf-8')
        print "Base64 Value = " + stringValue

else:
    print "Please enter a valid value."

PHPMailer: SMTP Error: Could not connect to SMTP host

I had the same problem and it was because PHPMailer realized the server supported STARTTLS so it tried to automatically upgrade the connection to an encrypted connection. My mail server is on the same subnet as the web server within my network which is all behind our domain firewalls so I'm not too worried about using encryption (plus the generated emails don't contain sensitive data anyway).

So what I went ahead and did was change the SMTPAutoTLS to false in the class.phpmailer.php file.

/**
 * Whether to enable TLS encryption automatically if a server supports it,
 * even if `SMTPSecure` is not set to 'tls'.
 * Be aware that in PHP >= 5.6 this requires that the server's certificates are valid.
 * @var boolean
 */
public $SMTPAutoTLS = false;

How to round up a number in Javascript?

I've been using @AndrewMarshall answer for a long time, but found some edge cases. The following tests doesn't pass:

equals(roundUp(9.69545, 4), 9.6955);
equals(roundUp(37.760000000000005, 4), 37.76);
equals(roundUp(5.83333333, 4), 5.8333);

Here is what I now use to have round up behave correctly:

// Closure
(function() {
  /**
   * Decimal adjustment of a number.
   *
   * @param {String}  type  The type of adjustment.
   * @param {Number}  value The number.
   * @param {Integer} exp   The exponent (the 10 logarithm of the adjustment base).
   * @returns {Number} The adjusted value.
   */
  function decimalAdjust(type, value, exp) {
    // If the exp is undefined or zero...
    if (typeof exp === 'undefined' || +exp === 0) {
      return Math[type](value);
    }
    value = +value;
    exp = +exp;
    // If the value is not a number or the exp is not an integer...
    if (isNaN(value) || !(typeof exp === 'number' && exp % 1 === 0)) {
      return NaN;
    }
    // If the value is negative...
    if (value < 0) {
      return -decimalAdjust(type, -value, exp);
    }
    // Shift
    value = value.toString().split('e');
    value = Math[type](+(value[0] + 'e' + (value[1] ? (+value[1] - exp) : -exp)));
    // Shift back
    value = value.toString().split('e');
    return +(value[0] + 'e' + (value[1] ? (+value[1] + exp) : exp));
  }

  // Decimal round
  if (!Math.round10) {
    Math.round10 = function(value, exp) {
      return decimalAdjust('round', value, exp);
    };
  }
  // Decimal floor
  if (!Math.floor10) {
    Math.floor10 = function(value, exp) {
      return decimalAdjust('floor', value, exp);
    };
  }
  // Decimal ceil
  if (!Math.ceil10) {
    Math.ceil10 = function(value, exp) {
      return decimalAdjust('ceil', value, exp);
    };
  }
})();

// Round
Math.round10(55.55, -1);   // 55.6
Math.round10(55.549, -1);  // 55.5
Math.round10(55, 1);       // 60
Math.round10(54.9, 1);     // 50
Math.round10(-55.55, -1);  // -55.5
Math.round10(-55.551, -1); // -55.6
Math.round10(-55, 1);      // -50
Math.round10(-55.1, 1);    // -60
Math.round10(1.005, -2);   // 1.01 -- compare this with Math.round(1.005*100)/100 above
Math.round10(-1.005, -2);  // -1.01
// Floor
Math.floor10(55.59, -1);   // 55.5
Math.floor10(59, 1);       // 50
Math.floor10(-55.51, -1);  // -55.6
Math.floor10(-51, 1);      // -60
// Ceil
Math.ceil10(55.51, -1);    // 55.6
Math.ceil10(51, 1);        // 60
Math.ceil10(-55.59, -1);   // -55.5
Math.ceil10(-59, 1);       // -50

Source: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/round

ImportError: No module named 'Tkinter'

You probably need to install it using one of (or something similar to) the following:

sudo apt-get install python3-tk 

You can also mention version number like this sudo apt-get install python3.7-tk for python 3.7.

sudo dnf install python3-tkinter

Why don't you try this and let me know if it worked:

try:
    # for Python2
    from Tkinter import *   ## notice capitalized T in Tkinter 
except ImportError:
    # for Python3
    from tkinter import *   ## notice lowercase 't' in tkinter here

Here is the reference link and here are the docs

Better to check versions as suggested here:

if sys.version_info[0] == 3:
    # for Python3
    from tkinter import *   ## notice lowercase 't' in tkinter here
else:
    # for Python2
    from Tkinter import *   ## notice capitalized T in Tkinter

Or you will get an error ImportError: No module named tkinter


Just to make this answer more generic I borrowed the following from Devendra Bhat's comment:

On Fedora please use either of the following commands

sudo dnf install python3-tkinter-3.6.6-1.fc28.x86_64

or

sudo dnf install python3-tkinter

Click toggle with jQuery

You could use the toggle function:

$('.offer').toggle(function() {
    $(this).find(':checkbox').attr('checked', true);
}, function() {
    $(this).find(':checkbox').attr('checked', false);
});

How to get a date in YYYY-MM-DD format from a TSQL datetime field?

This solution works for me, simple and effective (with 126 too)

CONVERT(NVARCHAR(MAX), CAST(GETDATE() as date), 120)

Object creation on the stack/heap?

In both your examples, local variables of Object* type are allocated on the stack. The compiler is free to produce the same code from both snippets if there is no way for your program to detect a difference.

The memory area for global variables is the same as the memory area for static variables - it's neither on the stack nor on the heap. You can place variables in that area by declaring them static inside the function. The consequence of doing so is that the instance becomes shared among concurrent invocations of your function, so you need to carefully consider synchronization when you use statics.

Here is a link to a discussion of the memory layout of a running C program.

How do I check CPU and Memory Usage in Java?

For memory usage, the following will work,

long total = Runtime.getRuntime().totalMemory();
long used  = Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory();

For CPU usage, you'll need to use an external application to measure it.

How to modify existing XML file with XmlDocument and XmlNode in C#

You need to do something like this:

// instantiate XmlDocument and load XML from file
XmlDocument doc = new XmlDocument();
doc.Load(@"D:\test.xml");

// get a list of nodes - in this case, I'm selecting all <AID> nodes under
// the <GroupAIDs> node - change to suit your needs
XmlNodeList aNodes = doc.SelectNodes("/Equipment/DataCollections/GroupAIDs/AID");

// loop through all AID nodes
foreach (XmlNode aNode in aNodes)
{
   // grab the "id" attribute
   XmlAttribute idAttribute = aNode.Attributes["id"];

   // check if that attribute even exists...
   if (idAttribute != null)
   {
      // if yes - read its current value
      string currentValue = idAttribute.Value;

      // here, you can now decide what to do - for demo purposes,
      // I just set the ID value to a fixed value if it was empty before
      if (string.IsNullOrEmpty(currentValue))
      {
         idAttribute.Value = "515";
      }
   }
}

// save the XmlDocument back to disk
doc.Save(@"D:\test2.xml");

How to import a jar in Eclipse

first of all you will go to your project what you are created and next right click in your mouse and select properties in the bottom and select build in path in the left corner and add external jar file add click apply .that's it

Android change SDK version in Eclipse? Unable to resolve target android-x

This can happen when you mistakenly import an Android project into your Eclipse workspace as a Java project. The solution in this case: delete the project from the workspace in the Package Explorer, then go to File -> Import -> Android -> Existing Android code into workspace.

How do I bind onchange event of a TextBox using JQuery?

Combination of keyup and change is not necessarily enough (browser's autocomplete and paste using mouse also changes the contents of a text box, but doesn't fire either of these events):

jquery change not working incase of dynamic value change

Model Binding to a List MVC 4

This is how I do it if I need a form displayed for each item, and inputs for various properties. Really depends on what I'm trying to do though.

ViewModel looks like this:

public class MyViewModel
{
   public List<Person> Persons{get;set;}
}

View(with BeginForm of course):

@model MyViewModel


@for( int i = 0; i < Model.Persons.Count(); ++i)
{
    @Html.HiddenFor(m => m.Persons[i].PersonId)
    @Html.EditorFor(m => m.Persons[i].FirstName) 
    @Html.EditorFor(m => m.Persons[i].LastName)         
}

Action:

[HttpPost]public ViewResult(MyViewModel vm)
{
...

Note that on post back only properties which had inputs available will have values. I.e., if Person had a .SSN property, it would not be available in the post action because it wasn't a field in the form.

Note that the way MVC's model binding works, it will only look for consecutive ID's. So doing something like this where you conditionally hide an item will cause it to not bind any data after the 5th item, because once it encounters a gap in the IDs, it will stop binding. Even if there were 10 people, you would only get the first 4 on the postback:

@for( int i = 0; i < Model.Persons.Count(); ++i)
{
    if(i != 4)//conditionally hide 5th item, 
    { //but BUG occurs on postback, all items after 5th will not be bound to the the list
      @Html.HiddenFor(m => m.Persons[i].PersonId)
      @Html.EditorFor(m => m.Persons[i].FirstName) 
      @Html.EditorFor(m => m.Persons[i].LastName)           
    }
}

Difference between Pig and Hive? Why have both?

Pig is useful for ETL kind of workloads generally speaking. For example set of transformations you need to do to your data every day.

Hive shines when you need to run adhoc queries or just want to explore data. It sometimes can act as interface to your visualisation Layer ( Tableau/Qlikview).

Both are essential and serve different purpose.

How to script FTP upload and download?

It's a reasonable idea to want to script an FTP session the way the original poster imagined, and that is the kind of thing Expect would help with. Batch files on Windows cannot do this.

But rather than doing cURL or Expect, you may find it easier to script the FTP interaction with Powershell. It's a different model, in that you are not directly scripting the text to send to the FTP server. Instead you will use Powershell to manipulate objects that generate the FTP dialogue for you.

Upload:

$File = "D:\Dev\somefilename.zip"
$ftp = "ftp://username:[email protected]/pub/incoming/somefilename.zip"

"ftp url: $ftp"

$webclient = New-Object System.Net.WebClient
$uri = New-Object System.Uri($ftp)

"Uploading $File..."

$webclient.UploadFile($uri, $File)

Download:

$File = "c:\store\somefilename.zip"
$ftp = "ftp://username:[email protected]/pub/outbound/somefilename.zip"

"ftp url: $ftp"

$webclient = New-Object System.Net.WebClient
$uri = New-Object System.Uri($ftp)

"Downloading $File..."

$webclient.DownloadFile($uri, $File)

You need Powershell to do this. If you are not aware, Powershell is a shell like cmd.exe which runs your .bat files. But Powershell runs .ps1 files, and is quite a bit more powerful. Powershell is a free add-on to Windows and will be built-in to future versions of Windows. Get it here.

Source: http://poshcode.org/1134

What online brokers offer APIs?

openecry.com is a broker with plenty of information on an API and instructions on how to do yours. There are also other brokers with the OEC platform and all the bells and whistles a pro could ask for.

How do I find which application is using up my port?

To see which ports are available on your machine run:

C:>  netstat -an |find /i "listening"

How to generate .NET 4.0 classes from xsd?

xsd.exe as mentioned by Marc Gravell. The fastest way to get up and running IMO.

Or if you need more flexibility/options :

xsd2code VS add-in (Codeplex)

How do I implement JQuery.noConflict() ?

/* The noConflict() method releases the hold on the $ shortcut identifier, so that other scripts can use it. */

 var jq = $.noConflict();
    (function($){
      $('document').ready(function(){
        $('button').click(function(){
          alert($('.para').text());
        })
      })
    })(jq);

Live view example on codepen that is easy to understand: http://codepen.io/kaushik/pen/QGjeJQ

Initialising a multidimensional array in Java

I'll add that if you want to read the dimensions, you can do this:

int[][][] a = new int[4][3][2];

System.out.println(a.length);  // 4
System.out.println(a[0].length); // 3
System.out.println(a[0][0].length); //2

You can also have jagged arrays, where different rows have different lengths, so a[0].length != a[1].length.

What tool can decompile a DLL into C++ source code?

There are no decompilers which I know about. W32dasm is good Win32 disassembler.

php mail setup in xampp

Unless you have a mail server set up on your local computer, setting SMTP = localhost won't have any effect.

In days gone by (long ago), it was sufficient to set the value of SMTP to the address of your ISP's SMTP server. This now rarely works because most ISPs insist on authentication with a username and password. However, the PHP mail() function doesn't support SMTP authentication. It's designed to work directly with the mail transport agent of the local server.

You either need to set up a local mail server or to use a PHP classs that supports SMTP authentication, such as Zend_Mail or PHPMailer. The simplest solution, however, is to upload your mail processing script to your remote server.

View content of H2 or HSQLDB in-memory database

This is more a comment to previous Thomas Mueller's post rather than an answer, but haven't got enough reputation for it. Another way of getting the connection if you are Spring JDBC Template is using the following:

jdbcTemplate.getDataSource().getConnection();

So on debug mode if you add to the "Expressions" view in Eclipse it will open the browser showing you the H2 Console:

org.h2.tools.Server.startWebServer(jdbcTemplate.getDataSource().getConnection());

Eclipse Expressions View

H2 Console

Open URL in Java to get the content

Are you sure using the java.net.URL class? Check your import statements.

Passing base64 encoded strings in URL

For url safe encode, like base64.urlsafe_b64encode(...) in Python the code below, works to me for 100%

function base64UrlSafeEncode(string $input)
{
   return str_replace(['+', '/'], ['-', '_'], base64_encode($input));
}

Optimal way to concatenate/aggregate strings

SOLUTION

The definition of optimal can vary, but here's how to concatenate strings from different rows using regular Transact SQL, which should work fine in Azure.

;WITH Partitioned AS
(
    SELECT 
        ID,
        Name,
        ROW_NUMBER() OVER (PARTITION BY ID ORDER BY Name) AS NameNumber,
        COUNT(*) OVER (PARTITION BY ID) AS NameCount
    FROM dbo.SourceTable
),
Concatenated AS
(
    SELECT 
        ID, 
        CAST(Name AS nvarchar) AS FullName, 
        Name, 
        NameNumber, 
        NameCount 
    FROM Partitioned 
    WHERE NameNumber = 1

    UNION ALL

    SELECT 
        P.ID, 
        CAST(C.FullName + ', ' + P.Name AS nvarchar), 
        P.Name, 
        P.NameNumber, 
        P.NameCount
    FROM Partitioned AS P
        INNER JOIN Concatenated AS C 
                ON P.ID = C.ID 
                AND P.NameNumber = C.NameNumber + 1
)
SELECT 
    ID,
    FullName
FROM Concatenated
WHERE NameNumber = NameCount

EXPLANATION

The approach boils down to three steps:

  1. Number the rows using OVER and PARTITION grouping and ordering them as needed for the concatenation. The result is Partitioned CTE. We keep counts of rows in each partition to filter the results later.

  2. Using recursive CTE (Concatenated) iterate through the row numbers (NameNumber column) adding Name values to FullName column.

  3. Filter out all results but the ones with the highest NameNumber.

Please keep in mind that in order to make this query predictable one has to define both grouping (for example, in your scenario rows with the same ID are concatenated) and sorting (I assumed that you simply sort the string alphabetically before concatenation).

I've quickly tested the solution on SQL Server 2012 with the following data:

INSERT dbo.SourceTable (ID, Name)
VALUES 
(1, 'Matt'),
(1, 'Rocks'),
(2, 'Stylus'),
(3, 'Foo'),
(3, 'Bar'),
(3, 'Baz')

The query result:

ID          FullName
----------- ------------------------------
2           Stylus
3           Bar, Baz, Foo
1           Matt, Rocks

Why can't I use a list as a dict key in python?

Your awnser can be found here:

Why Lists Can't Be Dictionary Keys

Newcomers to Python often wonder why, while the language includes both a tuple and a list type, tuples are usable as a dictionary keys, while lists are not. This was a deliberate design decision, and can best be explained by first understanding how Python dictionaries work.

Source & more info: http://wiki.python.org/moin/DictionaryKeys

Compare given date with today

Expanding on Josua's answer from w3schools:

//create objects for the dates to compare
$date1=date_create($someDate);
$date2=date_create(date("Y-m-d"));
$diff=date_diff($date1,$date2);
//now convert the $diff object to type integer
$intDiff = $diff->format("%R%a");
$intDiff = intval($intDiff);
//now compare the two dates
if ($intDiff > 0)  {echo '$date1 is in the past';}
else {echo 'date1 is today or in the future';}

I hope this helps. My first post on stackoverflow!

SQL Error: 0, SQLState: 08S01 Communications link failure

I'm answering on specific to this error code(08s01).

usually, MySql close socket connections are some interval of time that is wait_timeout defined on MySQL server-side which by default is 8hours. so if a connection will timeout after this time and the socket will throw an exception which SQLState is "08s01".

1.use connection pool to execute Query, make sure the pool class has a function to make an inspection of the connection members before it goes time_out.

2.give a value of <wait_timeout> greater than the default, but the largest value is 24 days

3.use another parameter in your connection URL, but this method is not recommended, and maybe deprecated.

How to change the color of a CheckBox?

you can set android theme of the checkbox to get the color you want in your styles.xml add :

<style name="checkBoxStyle" parent="Base.Theme.AppCompat">
    <item name="colorAccent">CHECKEDHIGHLIGHTCOLOR</item>
    <item name="android:textColorSecondary">UNCHECKEDCOLOR</item>
</style>

then in your layout file :

<CheckBox
     android:theme="@style/checkBoxStyle"
     android:id="@+id/chooseItemCheckBox"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"/>

unlike using android:buttonTint="@color/CHECK_COLOR" this method works under Api 23

How to tell if JRE or JDK is installed

according to JAVA documentation, the JDK should be installed in this path:

/Library/Java/JavaVirtualMachines/jdkmajor.minor.macro[_update].jdk

See the uninstall JDK part at https://docs.oracle.com/javase/8/docs/technotes/guides/install/mac_jdk.html

So if you can find such folder then the JDK is installed

setTimeout / clearTimeout problems

A way to use this in react:

class Timeout extends Component {
  constructor(props){
    super(props)

    this.state = {
      timeout: null
    }

  }

  userTimeout(){
    const { timeout } = this.state;
    clearTimeout(timeout);
    this.setState({
      timeout: setTimeout(() => {this.callAPI()}, 250)
    })

  }
}

Helpful if you'd like to only call an API after the user has stopped typing for instance. The userTimeout function could be bound via onKeyUp to an input.

Change Oracle port from port 8080

I assume you're talking about the Apache server that Oracle installs. Look for the file httpd.conf.

Open this file in a text editor and look for the line
Listen 8080
or
Listen {ip address}:8080

Change the port number and either restart the web server or just reboot the machine.

setting y-axis limit in matplotlib

This worked at least in matplotlib version 2.2.2:

plt.axis([None, None, 0, 100])

Probably this is a nice way to set up for example xmin and ymax only, etc.

The Network Adapter could not establish the connection when connecting with Oracle DB

Take a look at this post on Java Ranch:

http://www.coderanch.com/t/300287/JDBC/java/Io-Exception-Network-Adapter-could

"The solution for my "Io exception: The Network Adapter could not establish the connection" exception was to replace the IP of the database server to the DNS name."

How do I pass a string into subprocess.Popen (using the stdin argument)?

Apparently a cStringIO.StringIO object doesn't quack close enough to a file duck to suit subprocess.Popen

I'm afraid not. The pipe is a low-level OS concept, so it absolutely requires a file object that is represented by an OS-level file descriptor. Your workaround is the right one.

How to undo a successful "git cherry-pick"?

One command and does not use the destructive git reset command:

GIT_SEQUENCE_EDITOR="sed -i 's/pick/d/'" git rebase -i HEAD~ --autostash

It simply drops the commit, putting you back exactly in the state before the cherry-pick even if you had local changes.

Read lines from a text file but skip the first two lines

May be I am oversimplifying?

Just add the following code:

Open sFileName For Input as iFileNum
Line Input #iFileNum, dummy1
Line Input #iFileNum, dummy2
........

Sundar

Calling dynamic function with dynamic number of parameters

Use the apply method of a function:-

function mainfunc (func){
    window[func].apply(null, Array.prototype.slice.call(arguments, 1));
} 

Edit: It occurs to me that this would be much more useful with a slight tweak:-

function mainfunc (func){
    this[func].apply(this, Array.prototype.slice.call(arguments, 1));
} 

This will work outside of the browser (this defaults to the global space). The use of call on mainfunc would also work:-

function target(a) {
    alert(a)
}

var o = {
    suffix: " World",
    target: function(s) { alert(s + this.suffix); }
};

mainfunc("target", "Hello");

mainfunc.call(o, "target", "Hello");

ASP.NET file download from server

protected void DescargarArchivo(string strRuta, string strFile)
{
    FileInfo ObjArchivo = new System.IO.FileInfo(strRuta);
    Response.Clear();
    Response.AddHeader("Content-Disposition", "attachment; filename=" + strFile);
    Response.AddHeader("Content-Length", ObjArchivo.Length.ToString());
    Response.ContentType = "application/pdf";
    Response.WriteFile(ObjArchivo.FullName);
    Response.End();


}

Sorting an ArrayList of objects using a custom sorting order

In addition to what was already posted you should know that since Java 8 we can shorten our code and write it like:

Collection.sort(yourList, Comparator.comparing(YourClass::getFieldToSortOn));

or since List now have sort method

yourList.sort(Comparator.comparing(YourClass::getFieldToSortOn));

Explanation:

Since Java 8, functional interfaces (interfaces with only one abstract method - they can have more default or static methods) can be easily implemented using:

Since Comparator<T> has only one abstract method int compare(T o1, T o2) it is functional interface.

So instead of (example from @BalusC answer)

Collections.sort(contacts, new Comparator<Contact>() {
    public int compare(Contact one, Contact other) {
        return one.getAddress().compareTo(other.getAddress());
    }
}); 

we can reduce this code to:

Collections.sort(contacts, (Contact one, Contact other) -> {
     return one.getAddress().compareTo(other.getAddress());
});

We can simplify this (or any) lambda by skipping

  • argument types (Java will infer them based on method signature)
  • or {return ... }

So instead of

(Contact one, Contact other) -> {
     return one.getAddress().compareTo(other.getAddress();
}

we can write

(one, other) -> one.getAddress().compareTo(other.getAddress())

Also now Comparator has static methods like comparing(FunctionToComparableValue) or comparing(FunctionToValue, ValueComparator) which we could use to easily create Comparators which should compare some specific values from objects.

In other words we can rewrite above code as

Collections.sort(contacts, Comparator.comparing(Contact::getAddress)); 
//assuming that Address implements Comparable (provides default order).

WPF - add static items to a combo box

<ComboBox Text="Something">
            <ComboBoxItem Content="Item1"></ComboBoxItem >
            <ComboBoxItem Content="Item2"></ComboBoxItem >
            <ComboBoxItem Content="Item3"></ComboBoxItem >
</ComboBox>

When to use malloc for char pointers

As was indicated by others, you don't need to use malloc just to do:

const char *foo = "bar";

The reason for that is exactly that *foo is a pointer — when you initialize foo you're not creating a copy of the string, just a pointer to where "bar" lives in the data section of your executable. You can copy that pointer as often as you'd like, but remember, they're always pointing back to the same single instance of that string.

So when should you use malloc? Normally you use strdup() to copy a string, which handles the malloc in the background. e.g.

const char *foo = "bar";
char *bar = strdup(foo); /* now contains a new copy of "bar" */
printf("%s\n", bar);     /* prints "bar" */
free(bar);               /* frees memory created by strdup */

Now, we finally get around to a case where you may want to malloc if you're using sprintf() or, more safely snprintf() which creates / formats a new string.

char *foo = malloc(sizeof(char) * 1024);        /* buffer for 1024 chars */
snprintf(foo, 1024, "%s - %s\n", "foo", "bar"); /* puts "foo - bar\n" in foo */
printf(foo);                                    /* prints "foo - bar" */
free(foo);                                      /* frees mem from malloc */

How to make a Qt Widget grow with the window size?

In Designer, activate the centralWidget and assign a layout, e.g. horizontal or vertical layout. Then your QFormLayout will automatically resize.

Image of Designer

Always make sure, that all widgets have a layout! Otherwise, automatic resizing will break with that widget!

See also

Controls insist on being too large, and won't resize, in QtDesigner

Regular expression to match a dot

In javascript you have to use \. to match a dot.

Example

"blah.tests.zibri.org".match('test\\..*')
null

and

"blah.test.zibri.org".match('test\\..*')
["test.zibri.org", index: 5, input: "blah.test.zibri.org", groups: undefined]

PHP/regex: How to get the string value of HTML tag?

The following php snippets would return the text between html tags/elements.

regex : "/tagname(.*)endtag/" will return text between tags.

i.e.

$regex="/[start_tag_name](.*)[/end_tag_name]/";
$content="[start_tag_name]SOME TEXT[/end_tag_name]";
preg_replace($regex,$content); 

It will return "SOME TEXT".

Convert time span value to format "hh:mm Am/Pm" using C#

Parse timespan to DateTime and then use Format ("hh:mm:tt"). For example.

TimeSpan ts = new TimeSpan(16, 00, 00);
DateTime dtTemp = DateTime.ParseExact(ts.ToString(), "HH:mm:ss", CultureInfo.InvariantCulture);
string str = dtTemp.ToString("hh:mm tt");

str will be:

str = "04:00 PM"

How to lookup JNDI resources on WebLogic?

java is the root JNDI namespace for resources. What the original snippet of code means is that the container the application was initially deployed in did not apply any additional namespaces to the JNDI context you retrieved (as an example, Tomcat automatically adds all resources to the namespace comp/env, so you would have to do dataSource = (javax.sql.DataSource) context.lookup("java:comp/env/jdbc/myDataSource"); if the resource reference name is jdbc/myDataSource).

To avoid having to change your legacy code I think if you register the datasource with the name myDataSource (remove the jdbc/) you should be fine. Let me know if that works.

Binary numbers in Python

I think you're confused about what binary is. Binary and decimal are just different representations of a number - e.g. 101 base 2 and 5 base 10 are the same number. The operations add, subtract, and compare operate on numbers - 101 base 2 == 5 base 10 and addition is the same logical operation no matter what base you're working in. The fact that your python interpreter may store things as binary internally doesn't affect how you work with it - if you have an integer type, just use +, -, etc.

If you have strings of binary digits, you'll have to either write your own implementation or convert them using the int(binaryString, 2) function.

git stash changes apply to new branch?

Is the standard procedure not working?

  • make changes
  • git stash save
  • git branch xxx HEAD
  • git checkout xxx
  • git stash pop

Shorter:

  • make changes
  • git stash
  • git checkout -b xxx
  • git stash pop

Angular redirect to login page

Usage with the final router

With the introduction of the new router it became easier to guard the routes. You must define a guard, which acts as a service, and add it to the route.

import { Injectable } from '@angular/core';
import { CanActivate } from '@angular/router';
import { UserService } from '../../auth';

@Injectable()
export class LoggedInGuard implements CanActivate {
  constructor(user: UserService) {
    this._user = user;
  }

  canActivate() {
    return this._user.isLoggedIn();
  }
}

Now pass the LoggedInGuard to the route and also add it to the providers array of the module.

import { LoginComponent } from './components/login.component';
import { HomeComponent } from './components/home.component';
import { LoggedInGuard } from './guards/loggedin.guard';

const routes = [
    { path: '', component: HomeComponent, canActivate: [LoggedInGuard] },
    { path: 'login', component: LoginComponent },
];

The module declaration:

@NgModule({
  declarations: [AppComponent, HomeComponent, LoginComponent]
  imports: [HttpModule, BrowserModule, RouterModule.forRoot(routes)],
  providers: [UserService, LoggedInGuard],
  bootstrap: [AppComponent]
})
class AppModule {}

Detailed blog post about how it works with the final release: https://medium.com/@blacksonic86/angular-2-authentication-revisited-611bf7373bf9

Usage with the deprecated router

A more robust solution is to extend the RouterOutlet and when activating a route check if the user is logged in. This way you don't have to copy and paste your directive to every component. Plus redirecting based on a subcomponent can be misleading.

@Directive({
  selector: 'router-outlet'
})
export class LoggedInRouterOutlet extends RouterOutlet {
  publicRoutes: Array;
  private parentRouter: Router;
  private userService: UserService;

  constructor(
    _elementRef: ElementRef, _loader: DynamicComponentLoader,
    _parentRouter: Router, @Attribute('name') nameAttr: string,
    userService: UserService
  ) {
    super(_elementRef, _loader, _parentRouter, nameAttr);

    this.parentRouter = _parentRouter;
    this.userService = userService;
    this.publicRoutes = [
      '', 'login', 'signup'
    ];
  }

  activate(instruction: ComponentInstruction) {
    if (this._canActivate(instruction.urlPath)) {
      return super.activate(instruction);
    }

    this.parentRouter.navigate(['Login']);
  }

  _canActivate(url) {
    return this.publicRoutes.indexOf(url) !== -1 || this.userService.isLoggedIn()
  }
}

The UserService stands for the place where your business logic resides whether the user is logged in or not. You can add it easily with DI in the constructor.

When the user navigates to a new url on your website, the activate method is called with the current Instruction. From it you can grab the url and decide whether it is allowed or not. If not just redirect to the login page.

One last thing remain to make it work, is to pass it to our main component instead of the built in one.

@Component({
  selector: 'app',
  directives: [LoggedInRouterOutlet],
  template: template
})
@RouteConfig(...)
export class AppComponent { }

This solution can not be used with the @CanActive lifecycle decorator, because if the function passed to it resolves false, the activate method of the RouterOutlet won't be called.

Also wrote a detailed blog post about it: https://medium.com/@blacksonic86/authentication-in-angular-2-958052c64492

Build project into a JAR automatically in Eclipse

Using Thomas Bratt's answer above, just make sure your build.xml is configured properly :

<?xml version="1.0" ?>
<!-- Configuration of the Ant build system to generate a Jar file --> 
<project name="TestMain" default="CreateJar">
  <target name="CreateJar" description="Create Jar file">
        <jar jarfile="Test.jar" basedir="bin/" includes="**/*.class" />
  </target>
</project>

(Notice the double asterisk - it will tell build to look for .class files in all sub-directories.)

How to pass multiple values to single parameter in stored procedure

This can not be done easily. There's no way to make an NVARCHAR parameter take "more than one value". What I've done before is - as you do already - make the parameter value like a list with comma-separated values. Then, split this string up into its parts in the stored procedure.

Splitting up can be done using string functions. Add every part to a temporary table. Pseudo-code for this could be:

CREATE TABLE #TempTable (ID INT)
WHILE LEN(@PortfolioID) > 0
BEGIN
    IF NOT <@PortfolioID contains Comma>
    BEGIN
        INSERT INTO #TempTable VALUES CAST(@PortfolioID as INT)
        SET @PortfolioID = ''
    END ELSE
    BEGIN
         INSERT INTO #Temptable VALUES CAST(<Part until next comma> AS INT)
         SET @PortfolioID = <Everything after the next comma>
    END
END

Then, change your condition to

WHERE PortfolioId IN (SELECT ID FROM #TempTable)

EDIT
You may be interested in the documentation for multi value parameters in SSRS, which states:

You can define a multivalue parameter for any report parameter that you create. However, if you want to pass multiple parameter values back to a data source by using the query, the following requirements must be satisfied:

The data source must be SQL Server, Oracle, Analysis Services, SAP BI NetWeaver, or Hyperion Essbase.

The data source cannot be a stored procedure. Reporting Services does not support passing a multivalue parameter array to a stored procedure.

The query must use an IN clause to specify the parameter.

This I found here.

Java POI : How to read Excel cell value and not the formula computing it?

For formula cells, excel stores two things. One is the Formula itself, the other is the "cached" value (the last value that the forumla was evaluated as)

If you want to get the last cached value (which may no longer be correct, but as long as Excel saved the file and you haven't changed it it should be), you'll want something like:

 for(Cell cell : row) {
     if(cell.getCellType() == Cell.CELL_TYPE_FORMULA) {
        System.out.println("Formula is " + cell.getCellFormula());
        switch(cell.getCachedFormulaResultType()) {
            case Cell.CELL_TYPE_NUMERIC:
                System.out.println("Last evaluated as: " + cell.getNumericCellValue());
                break;
            case Cell.CELL_TYPE_STRING:
                System.out.println("Last evaluated as \"" + cell.getRichStringCellValue() + "\"");
                break;
        }
     }
 }

REST HTTP status codes for failed validation or invalid duplicate

For input validation failure: 400 Bad Request + your optional description. This is suggested in the book "RESTful Web Services". For double submit: 409 Conflict


Update June 2014

The relevant specification used to be RFC2616, which gave the use of 400 (Bad Request) rather narrowly as

The request could not be understood by the server due to malformed syntax

So it might have been argued that it was inappropriate for semantic errors. But not any more; since June 2014 the relevant standard RFC 7231, which supersedes the previous RFC2616, gives the use of 400 (Bad Request) more broadly as

the server cannot or will not process the request due to something that is perceived to be a client error

How to update record using Entity Framework 6?

So you have an entity that is updated, and you want to update it in the database with the least amount of code...

Concurrency is always tricky, but I am assuming that you just want your updates to win. Here is how I did it for my same case and modified the names to mimic your classes. In other words, just change attach to add, and it works for me:

public static void SaveBook(Model.Book myBook)
{
    using (var ctx = new BookDBContext())
    {
        ctx.Books.Add(myBook);
        ctx.Entry(myBook).State = System.Data.Entity.EntityState.Modified;
        ctx.SaveChanges();
    }
}

How to install mcrypt extension in xampp

The recent versions of XAMPP for Windows runs PHP 7.x which are NOT compatible with mbcrypt. If you have a package like Laravel that requires mbcrypt, you will need to install an older version of XAMPP. OR, you can run XAMPP with multiple versions of PHP by downloading a PHP package from Windows.PHP.net, installing it in your XAMPP folder, and configuring php.ini and httpd.conf to use the correct version of PHP for your site.

Using CSS to affect div style inside iframe

Yes, it's possible although cumbersome. You would need to print/echo the HTML of the page into the body of your page then apply a CSS rule change function. Using the same examples given above, you would essentially be using a parsing method of finding the divs in the page, and then applying the CSS to it and then reprinting/echoing it out to the end user. I don't need this so I don't want to code that function into every item in the CSS of another webpage just to aphtply.

References:

Add new field to every document in a MongoDB collection

Since MongoDB version 3.2 you can use updateMany():

> db.yourCollection.updateMany({}, {$set:{"someField": "someValue"}})

Convert character to ASCII numeric value in java

If you want the ASCII value of all the characters in a String. You can use this :

String a ="asdasd";
int count =0;
for(int i : a.toCharArray())
    count+=i;

and if you want ASCII of a single character in a String you can go for :

(int)a.charAt(index);

Remove specific characters from a string in Python

You can also use a function in order to substitute different kind of regular expression or other pattern with the use of a list. With that, you can mixed regular expression, character class, and really basic text pattern. It's really useful when you need to substitute a lot of elements like HTML ones.

*NB: works with Python 3.x

import re  # Regular expression library


def string_cleanup(x, notwanted):
    for item in notwanted:
        x = re.sub(item, '', x)
    return x

line = "<title>My example: <strong>A text %very% $clean!!</strong></title>"
print("Uncleaned: ", line)

# Get rid of html elements
html_elements = ["<title>", "</title>", "<strong>", "</strong>"]
line = string_cleanup(line, html_elements)
print("1st clean: ", line)

# Get rid of special characters
special_chars = ["[!@#$]", "%"]
line = string_cleanup(line, special_chars)
print("2nd clean: ", line)

In the function string_cleanup, it takes your string x and your list notwanted as arguments. For each item in that list of elements or pattern, if a substitute is needed it will be done.

The output:

Uncleaned:  <title>My example: <strong>A text %very% $clean!!</strong></title>
1st clean:  My example: A text %very% $clean!!
2nd clean:  My example: A text very clean

How to append binary data to a buffer in node.js

This is to help anyone who comes here looking for a solution that wants a pure approach. I would recommend understanding this problem because it can happen in lots of different places not just with a JS Buffer object. By understanding why the problem exists and how to solve it you will improve your ability to solve other problems in the future since this one is so fundamental.

For those of us that have to deal with these problems in other languages it is quite natural to devise a solution, but there are people who may not realize how to abstract away the complexities and implement a generally efficient dynamic buffer. The code below may have potential to be optimized further.

I have left the read method unimplemented to keep the example small in size.

The realloc function in C (or any language dealing with intrinsic allocations) does not guarantee that the allocation will be expanded in size with out moving the existing data - although sometimes it is possible. Therefore most applications when needing to store a unknown amount of data will use a method like below and not constantly reallocate, unless the reallocation is very infrequent. This is essentially how most file systems handle writing data to a file. The file system simply allocates another node and keeps all the nodes linked together, and when you read from it the complexity is abstracted away so that the file/buffer appears to be a single contiguous buffer.

For those of you who wish to understand the difficulty in just simply providing a high performance dynamic buffer you only need to view the code below, and also do some research on memory heap algorithms and how the memory heap works for programs.

Most languages will provide a fixed size buffer for performance reasons, and then provide another version that is dynamic in size. Some language systems opt for a third-party system where they keep the core functionality minimal (core distribution) and encourage developers to create libraries to solve additional or higher level problems. This is why you may question why a language does not provide some functionality. This small core functionality allows costs to be reduced in maintaining and enhancing the language, however you end up having to write your own implementations or depending on a third-party.

var Buffer_A1 = function (chunk_size) {
    this.buffer_list = [];
    this.total_size = 0;
    this.cur_size = 0;
    this.cur_buffer = [];
    this.chunk_size = chunk_size || 4096;

    this.buffer_list.push(new Buffer(this.chunk_size));
};

Buffer_A1.prototype.writeByteArrayLimited = function (data, offset, length) {
    var can_write = length > (this.chunk_size - this.cur_size) ? (this.chunk_size - this.cur_size) : length;

    var lastbuf = this.buffer_list.length - 1;

    for (var x = 0; x < can_write; ++x) {
        this.buffer_list[lastbuf][this.cur_size + x] = data[x + offset];
    }

    this.cur_size += can_write;
    this.total_size += can_write;

    if (this.cur_size == this.chunk_size) {
        this.buffer_list.push(new Buffer(this.chunk_size));
        this.cur_size = 0;
    }

    return can_write;
};

/*
    The `data` parameter can be anything that is array like. It just must
    support indexing and a length and produce an acceptable value to be
    used with Buffer.
*/
Buffer_A1.prototype.writeByteArray = function (data, offset, length) {
    offset = offset == undefined ? 0 : offset;
    length = length == undefined ? data.length : length;

    var rem = length;
    while (rem > 0) {
        rem -= this.writeByteArrayLimited(data, length - rem, rem);
    }
};

Buffer_A1.prototype.readByteArray = function (data, offset, length) {
    /*
        If you really wanted to implement some read functionality
        then you would have to deal with unaligned reads which could
        span two buffers.
    */
};

Buffer_A1.prototype.getSingleBuffer = function () {
    var obuf = new Buffer(this.total_size);
    var cur_off = 0;
    var x;

    for (x = 0; x < this.buffer_list.length - 1; ++x) {
        this.buffer_list[x].copy(obuf, cur_off);
        cur_off += this.buffer_list[x].length;
    }

    this.buffer_list[x].copy(obuf, cur_off, 0, this.cur_size);

    return obuf;
};

Sort array by firstname (alphabetically) in Javascript

try

users.sort((a,b)=> (a.firstname>b.firstname)*2-1)

_x000D_
_x000D_
var users = [_x000D_
  { firstname: "Kate", id: 318, /*...*/ },_x000D_
  { firstname: "Anna", id: 319, /*...*/ },_x000D_
  { firstname: "Cristine", id: 317, /*...*/ },_x000D_
]_x000D_
_x000D_
console.log(users.sort((a,b)=> (a.firstname>b.firstname)*2-1) );
_x000D_
_x000D_
_x000D_

You must add a reference to assembly 'netstandard, Version=2.0.0.0

Although this is an old thread, I had the same issue today, last week I updated some NuGet packages and although the MVC website worked OK on my dev machine when I published to the testing server it failed.

I read numerous posts but none worked. I finally compared the DLL's in my local bin to those in the testing server and found that the netstandard.dll was not uploaded, once uploaded the website worked OK, not sure why VS2017 web deploy did not publish the DLL.

Just something to look out for in case none of the above work for you.

What is the proper way to re-attach detached objects in Hibernate?

All of these answers miss an important distinction. update() is used to (re)attach your object graph to a Session. The objects you pass it are the ones that are made managed.

merge() is actually not a (re)attachment API. Notice merge() has a return value? That's because it returns you the managed graph, which may not be the graph you passed it. merge() is a JPA API and its behavior is governed by the JPA spec. If the object you pass in to merge() is already managed (already associated with the Session) then that's the graph Hibernate works with; the object passed in is the same object returned from merge(). If, however, the object you pass into merge() is detached, Hibernate creates a new object graph that is managed and it copies the state from your detached graph onto the new managed graph. Again, this is all dictated and governed by the JPA spec.

In terms of a generic strategy for "make sure this entity is managed, or make it managed", it kind of depends on if you want to account for not-yet-inserted data as well. Assuming you do, use something like

if ( session.contains( myEntity ) ) {
    // nothing to do... myEntity is already associated with the session
}
else {
    session.saveOrUpdate( myEntity );
}

Notice I used saveOrUpdate() rather than update(). If you do not want not-yet-inserted data handled here, use update() instead...

Eclipse can't find / load main class

I had this same problem in a Maven project. After creating the src/test/java folder within the project the error went away.

Using Javascript can you get the value from a session attribute set by servlet in the HTML page

<%
String session_val = (String)session.getAttribute("sessionval"); 
System.out.println("session_val"+session_val);
%>
<html>
<head>
<script type="text/javascript">
var session_obj= '<%=session_val%>';
alert("session_obj"+session_obj);
</script>
</head>
</html>

How to exclude a directory in find . command

There are plenty of good answers, it just took me some time to understand what each element of the command was for and the logic behind it.

find . -path ./misc -prune -o -name '*.txt' -print

find will start finding files and directories in the current directory, hence the find ..

The -o option stands for a logical OR and separates the two parts of the command :

[ -path ./misc -prune ] OR [ -name '*.txt' -print ]

Any directory or file that is not the ./misc directory will not pass the first test -path ./misc. But they will be tested against the second expression. If their name corresponds to the pattern *.txt they get printed, because of the -print option.

When find reaches the ./misc directory, this directory only satisfies the first expression. So the -prune option will be applied to it. It tells the find command to not explore that directory. So any file or directory in ./misc will not even be explored by find, will not be tested against the second part of the expression and will not be printed.

How to pipe list of files returned by find command to cat to view all the files

There are a few ways to pass the list of files returned by the find command to the cat command, though technically not all use piping, and none actually pipe directly to cat.

  1. The simplest is to use backticks (`):

    cat `find [whatever]`
    

    This takes the output of find and effectively places it on the command line of cat. This doesn't work well if find has too much output (more than can fit on a command-line) or if the output has special characters (like spaces).

  2. In some shells, including bash, one can use $() instead of backticks :

    cat $(find [whatever])
    

    This is less portable, but is nestable. Aside from that, it has pretty much the same caveats as backticks.

  3. Because running other commands on what was found is a common use for find, find has an -exec action which executes a command for each file it finds:

    find [whatever] -exec cat {} \;
    

    The {} is a placeholder for the filename, and the \; marks the end of the command (It's possible to have other actions after -exec.)

    This will run cat once for every single file rather than running a single instance of cat passing it multiple filenames which can be inefficient and might not have the behavior you want for some commands (though it's fine for cat). The syntax is also a awkward to type -- you need to escape the semicolon because semicolon is special to the shell!

  4. Some versions of find (most notably the GNU version) let you replace ; with + to use -exec's append mode to run fewer instances of cat:

    find [whatever] -exec cat {} +
    

    This will pass multiple filenames to each invocation of cat, which can be more efficient.

    Note that this is not guaranteed to use a single invocation, however. If the command line would be too long then the arguments are spread across multiple invocations of cat. For cat this is probably not a big deal, but for some other commands this may change the behavior in undesirable ways. On Linux systems, the command line length limit is quite large, so splitting into multiple invocations is quite rare compared to some other OSes.

  5. The classic/portable approach is to use xargs:

    find [whatever] | xargs cat
    

    xargs runs the command specified (cat, in this case), and adds arguments based on what it reads from stdin. Just like -exec with +, this will break up the command-line if necessary. That is, if find produces too much output, it'll run cat multiple times. As mentioned in the section about -exec earlier, there are some commands where this splitting may result in different behavior. Note that using xargs like this has issues with spaces in filenames, as xargs just uses whitespace as a delimiter.

  6. The most robust, portable, and efficient method also uses xargs:

    find [whatever] -print0 | xargs -0 cat
    

    The -print0 flag tells find to use \0 (null character) delimiters between filenames, and the -0 flag tells xargs to expect these \0 delimiters. This has pretty much identical behavior to the -exec...+ approach, though is more portable (but unfortunately more verbose).

How to find duplicate records in PostgreSQL

The basic idea will be using a nested query with count aggregation:

select * from yourTable ou
where (select count(*) from yourTable inr
where inr.sid = ou.sid) > 1

You can adjust the where clause in the inner query to narrow the search.


There is another good solution for that mentioned in the comments, (but not everyone reads them):

select Column1, Column2, count(*)
from yourTable
group by Column1, Column2
HAVING count(*) > 1

Or shorter:

SELECT (yourTable.*)::text, count(*)
FROM yourTable
GROUP BY yourTable.*
HAVING count(*) > 1

MySQL error code: 1175 during UPDATE in MySQL Workbench

SET SQL_SAFE_UPDATES=0;
UPDATE tablename SET columnname=1;
SET SQL_SAFE_UPDATES=1;

JQuery show/hide when hover

I hope my script help you.

<i class="mostrar-producto">mostrar...</i>
<div class="producto" style="display:none;position: absolute;">Producto</div>

My script

<script>
$(".mostrar-producto").mouseover(function(){
     $(".producto").fadeIn();
 });

 $(".mostrar-producto").mouseleave(function(){
      $(".producto").fadeOut();
  });
</script>

Get most recent row for given ID

Building on @xQbert's answer's, you can avoid the subquery AND make it generic enough to filter by any ID

SELECT id, signin, signout
FROM dTable
INNER JOIN(
  SELECT id, MAX(signin) AS signin
  FROM dTable
  GROUP BY id
) AS t1 USING(id, signin)

How do you see recent SVN log entries?

limit option, e.g.:

svn log --limit 4

svn log -l 4

Only the last 4 entries

JavaScript query string

Or you could use the library sugar.js.

From sugarjs.com:

Object.fromQueryString ( str , deep = true )

Converts the query string of a URL into an object. If deep is false, conversion will only accept shallow params (ie. no object or arrays with [] syntax) as these are not universally supported.

Object.fromQueryString('foo=bar&broken=wear') >{"foo":"bar","broken":"wear"}
Object.fromQueryString('foo[]=1&foo[]=2') >{"foo":[1,2]}

Example:

var queryString = Object.fromQueryString(location.search);
var foo = queryString.foo;

How to get row data by clicking a button in a row in an ASP.NET gridview

Place the commandName in .aspx page

 <asp:Button  ID="btnDelete" Text="Delete" runat="server" CssClass="CoolButtons" CommandName="DeleteData"/>

Subscribe the rowCommand event for the grid and you can try like this,

protected void grdBillingdata_RowCommand(object sender, GridViewCommandEventArgs e)
{
        if (e.CommandName == "DeleteData")
        {
            GridViewRow row = (GridViewRow)(((Button)e.CommandSource).NamingContainer);
            HiddenField hdnDataId = (HiddenField)row.FindControl("hdnDataId");
         }
}

How to display a content in two-column layout in LaTeX?

Load the multicol package, like this \usepackage{multicol}. Then use:

\begin{multicols}{2}
Column 1
\columnbreak
Column 2
\end{multicols}

If you omit the \columnbreak, the columns will balance automatically.

How to get a Char from an ASCII Character Code in c#

It is important to notice that in C# the char type is stored as Unicode UTF-16.

From ASCII equivalent integer to char

char c = (char)88;

or

char c = Convert.ToChar(88)

From char to ASCII equivalent integer

int asciiCode = (int)'A';

The literal must be ASCII equivalent. For example:

string str = "X?????????";
Console.WriteLine((int)str[0]);
Console.WriteLine((int)str[1]);

will print

X
3626

Extended ASCII ranges from 0 to 255.

From default UTF-16 literal to char

Using the Symbol

char c = 'X';

Using the Unicode code

char c = '\u0058';

Using the Hexadecimal

char c = '\x0058';

What is the difference between T(n) and O(n)?

f(n) belongs to O(n) if exists positive k as f(n)<=k*n

f(n) belongs to T(n) if exists positive k1, k2 as k1*n<=f(n)<=k2*n

Wikipedia article on Big O Notation

How to make a view with rounded corners?

If you are having problem while adding touch listeners to the layout. Use this layout as parent layout.

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.graphics.Region;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.util.TypedValue;
import android.view.View;
import android.widget.FrameLayout;

public class RoundedCornerLayout extends FrameLayout {
    private final static float CORNER_RADIUS = 6.0f;
    private float cornerRadius;

    public RoundedCornerLayout(Context context) {
        super(context);
        init(context, null, 0);
    }

    public RoundedCornerLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context, attrs, 0);
    }

    public RoundedCornerLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init(context, attrs, defStyle);
    }

    private void init(Context context, AttributeSet attrs, int defStyle) {
        DisplayMetrics metrics = context.getResources().getDisplayMetrics();
        cornerRadius = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, CORNER_RADIUS, metrics);
        setLayerType(View.LAYER_TYPE_SOFTWARE, null);
    }


    @Override
    protected void dispatchDraw(Canvas canvas) {
        int count = canvas.save();

        final Path path = new Path();
        path.addRoundRect(new RectF(0, 0, canvas.getWidth(), canvas.getHeight()), cornerRadius, cornerRadius, Path.Direction.CW);
        canvas.clipPath(path, Region.Op.REPLACE);

        canvas.clipPath(path);
        super.dispatchDraw(canvas);
        canvas.restoreToCount(count);
    }


}

as

<?xml version="1.0" encoding="utf-8"?>
<com.example.view.RoundedCornerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <RelativeLayout
        android:id="@+id/patentItem"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:paddingRight="20dp">
        ... your child goes here
    </RelativeLayout>
</com.example.view.RoundedCornerLayout>

How do you find out the caller function in JavaScript?

Try accessing this:

arguments.callee.caller.name

sqlplus error on select from external table: ORA-29913: error in executing ODCIEXTTABLEOPEN callout

Our version of Oracle is running on Red Hat Enterprise Linux. We experimented with several different types of group permissions to no avail. The /defaultdir directory had a group that was a secondary group for the oracle user. When we updated the /defaultdir directory to have a group of "oinstall" (oracle's primary group), I was able to select from the external tables underneath that directory with no problem.

So, for others that come along and might have this issue, make the directory have oracle's primary group as the group and it might resolve it for you as it did us. We were able to set the permissions to 770 on the directory and files and selecting on the external tables works fine now.

Finding the direction of scrolling in a UIScrollView?

Alternatively, it is possible to observe key path "contentOffset". This is useful when it's not possible for you to set/change the delegate of the scroll view.

[yourScrollView addObserver:self forKeyPath:@"contentOffset" options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld context:nil];

After adding the observer, you could now:

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context{
    CGFloat newOffset = [[change objectForKey:@"new"] CGPointValue].y;
    CGFloat oldOffset = [[change objectForKey:@"old"] CGPointValue].y;
    CGFloat diff = newOffset - oldOffset;
    if (diff < 0 ) { //scrolling down
        // do something
    }
}

Do remember to remove the observer when needed. e.g. you could add the observer in viewWillAppear and remove it in viewWillDisappear

disabling spring security in spring boot app

Use @profile("whatever-name-profile-to-activate-if-needed") on your security configuration class that extends WebSecurityConfigurerAdapter

security.ignored=/**

security.basic.enable: false

NB. I need to debug to know why why exclude auto configuration did not work for me. But the profile is sot so bad as you can still re-activate it via configuration properties if needed

How to check if a database exists in SQL Server?

Actually it's best to use:

IF DB_ID('dms') IS NOT NULL
   --code mine :)
   print 'db exists'

See https://docs.microsoft.com/en-us/sql/t-sql/functions/db-id-transact-sql and note that this does not make sense with the Azure SQL Database.

how to realize countifs function (excel) in R

Given a dataset

df <- data.frame( sex = c('M', 'M', 'F', 'F', 'M'), 
                  occupation = c('analyst', 'dentist', 'dentist', 'analyst', 'cook') )

you can subset rows

df[df$sex == 'M',] # To get all males
df[df$occupation == 'analyst',] # All analysts

etc.

If you want to get number of rows, just call the function nrow such as

nrow(df[df$sex == 'M',])

How to find the privileges and roles granted to a user in Oracle?

Look at http://docs.oracle.com/cd/B10501_01/server.920/a96521/privs.htm#15665

Check USER_SYS_PRIVS, USER_TAB_PRIVS, USER_ROLE_PRIVS tables with these select statements

SELECT * FROM USER_SYS_PRIVS; 
SELECT * FROM USER_TAB_PRIVS; 
SELECT * FROM USER_ROLE_PRIVS;

Upgrade python in a virtualenv

On OS X or macOS using Homebrew to install and upgrade Python3 I had to delete symbolic links before python -m venv --upgrade ENV_DIR would work.

I saved the following in upgrade_python3.sh so I would remember how months from now when I need to do it again:

brew upgrade python3
find ~/.virtualenvs/ -type l -delete
find ~/.virtualenvs/ -type d -mindepth 1 -maxdepth 1 -exec python3 -m venv --upgrade "{}" \;

UPDATE: while this seemed to work well at first, when I ran py.test it gave an error. In the end I just re-created the environment from a requirements file.

ActiveXObject creation error " Automation server can't create object"

I have the same problem , it solved by registering the dll

at project properties => build => register for COM interop => check it

gnuplot - adjust size of key/legend

To adjust the length of the samples:

set key samplen X

(default is 4)

To adjust the vertical spacing of the samples:

set key spacing X

(default is 1.25)

and (for completeness), to adjust the fontsize:

set key font "<face>,<size>"

(default depends on the terminal)

And of course, all these can be combined into one line:

set key samplen 2 spacing .5 font ",8"

Note that you can also change the position of the key using set key at <position> or any one of the pre-defined positions (which I'll just defer to help key at this point)

How does a Java HashMap handle different objects with the same hash code?

Your third assertion is incorrect.

It's perfectly legal for two unequal objects to have the same hash code. It's used by HashMap as a "first pass filter" so that the map can quickly find possible entries with the specified key. The keys with the same hash code are then tested for equality with the specified key.

You wouldn't want a requirement that two unequal objects couldn't have the same hash code, as otherwise that would limit you to 232 possible objects. (It would also mean that different types couldn't even use an object's fields to generate hash codes, as other classes could generate the same hash.)

Change HTML email body font type and size in VBA

I did a little research and was able to write this code:

strbody = "<BODY style=font-size:11pt;font-family:Calibri>Good Morning;<p>We have completed our main aliasing process for today.  All assigned firms are complete.  Please feel free to respond with any questions.<p>Thank you.</BODY>"

apparently by setting the "font-size=11pt" instead of setting the font size <font size=5>, It allows you to select a specific font size like you normally would in a text editor, as opposed to selecting a value from 1-7 like my code was originally.

This link from simpLE MAn gave me some good info.

Find the max of 3 numbers in Java with different data types

You can do like this:

public static void main(String[] args) {

    int x=2 , y=7, z=14;
    int max1= Math.max(x,y);

    System.out.println("Max value is: "+ Math.max(max1, z)); 
}  

node.js Error: connect ECONNREFUSED; response from server

I got this error because my AdonisJS server was not running before I ran the test. Running the server first fixed it.

How can I set / change DNS using the command-prompt at windows 8

None of the answers are working for me on Windows 10, so here's what I use:

@echo off

set DNS1=8.8.8.8
set DNS2=8.8.4.4
set INTERFACE=Ethernet

netsh int ipv4 set dns name="%INTERFACE%" static %DNS1% primary validate=no
netsh int ipv4 add dns name="%INTERFACE%" %DNS2% index=2

ipconfig /flushdns

pause

This uses Google DNS. You can get interface name with the command netsh int show interface

ArrayList insertion and retrieval order

Yes, ArrayList is an ordered collection and it maintains the insertion order.

Check the code below and run it:

public class ListExample {

    public static void main(String[] args) {
        List<String> myList = new ArrayList<String>();
        myList.add("one");
        myList.add("two");
        myList.add("three");
        myList.add("four");
        myList.add("five");
    
        System.out.println("Inserted in 'order': ");
        printList(myList);
        System.out.println("\n");
        System.out.println("Inserted out of 'order': ");

        // Clear the list
        myList.clear();
    
        myList.add("four");
        myList.add("five");
        myList.add("one");
        myList.add("two");
        myList.add("three");
    
        printList(myList);
    }

    private static void printList(List<String> myList) {
        for (String string : myList) {
            System.out.println(string);
        }
    }
}

Produces the following output:

Inserted in 'order': 
one
two
three
four
five


Inserted out of 'order': 
four
five
one
two
three

For detailed information, please refer to documentation: List (Java Platform SE7)

How to duplicate a whole line in Vim?

1 gotcha: when you use "p" to put the line, it puts it after the line your cursor is on, so if you want to add the line after the line you're yanking, don't move the cursor down a line before putting the new line.

Subclipse svn:ignore

What worked for me was following : (eclipse 3.3.6 Subclipse 2.4)

  • set svn:ignore property via tortoise : ( .settings .classpath .project target .apt_src one item at one line)
  • deleted the project from the eclipse
  • fresh checkout from the svn
  • import the project in eclipse (simple reimporting the project in eclipse did not worked for me)

Select second last element with css

Note: Posted this answer because OP later stated in comments that they need to select the last two elements, not just the second to last one.


The :nth-child CSS3 selector is in fact more capable than you ever imagined!

For example, this will select the last 2 elements of #container:

#container :nth-last-child(-n+2) {}

But this is just the beginning of a beautiful friendship.

_x000D_
_x000D_
#container :nth-last-child(-n+2) {
  background-color: cyan;
}
_x000D_
<div id="container">
 <div>a</div>
 <div>b</div>
 <div>SELECT THIS</div>
 <div>SELECT THIS</div>
</div>
_x000D_
_x000D_
_x000D_

How to pass command line arguments to a shell alias?

You cannot in ksh, but you can in csh.

alias mkcd 'mkdir \!^; cd \!^1'

In ksh, function is the way to go. But if you really really wanted to use alias:

alias mkcd='_(){ mkdir $1; cd $1; }; _'

What is key=lambda

A lambda is an anonymous function:

>>> f = lambda: 'foo'
>>> print f()
foo

It is often used in functions such as sorted() that take a callable as a parameter (often the key keyword parameter). You could provide an existing function instead of a lambda there too, as long as it is a callable object.

Take the sorted() function as an example. It'll return the given iterable in sorted order:

>>> sorted(['Some', 'words', 'sort', 'differently'])
['Some', 'differently', 'sort', 'words']

but that sorts uppercased words before words that are lowercased. Using the key keyword you can change each entry so it'll be sorted differently. We could lowercase all the words before sorting, for example:

>>> def lowercased(word): return word.lower()
...
>>> lowercased('Some')
'some'
>>> sorted(['Some', 'words', 'sort', 'differently'], key=lowercased)
['differently', 'Some', 'sort', 'words']

We had to create a separate function for that, we could not inline the def lowercased() line into the sorted() expression:

>>> sorted(['Some', 'words', 'sort', 'differently'], key=def lowercased(word): return word.lower())
  File "<stdin>", line 1
    sorted(['Some', 'words', 'sort', 'differently'], key=def lowercased(word): return word.lower())
                                                           ^
SyntaxError: invalid syntax

A lambda on the other hand, can be specified directly, inline in the sorted() expression:

 >>> sorted(['Some', 'words', 'sort', 'differently'], key=lambda word: word.lower())
['differently', 'Some', 'sort', 'words']

Lambdas are limited to one expression only, the result of which is the return value.

There are loads of places in the Python library, including built-in functions, that take a callable as keyword or positional argument. There are too many to name here, and they often play a different role.

Is there a Visual Basic 6 decompiler?

http://www.program-transformation.org/Transform/VisualBasicDecompilers

This link provides a lot of resources for VB6 Decompiling, but it seems like it will depend greatly on what you DO have (do you still have the pre-link Object code [EDIT: er... p-code I mean], or just the EXE?) Either way, it looks like there's something, take a look in there.

sklearn: Found arrays with inconsistent numbers of samples when calling LinearRegression.fit()

Some days I faced the same problem. Reason was different sizes arrays.

fatal: Not a valid object name: 'master'

Git creates a master branch once you've done your first commit. There's nothing to have a branch for if there's no code in the repository.

How to use img src in vue.js?

Try this:

<img v-bind:src="'/media/avatars/' + joke.avatar" /> 

Don't forget single quote around your path string. also in your data check you have correctly defined image variable.

joke: {
  avatar: 'image.jpg'
}

A working demo here: http://jsbin.com/pivecunode/1/edit?html,js,output

Initializing a static std::map<int, int> in C++

If you are stuck with C++98 and don't want to use boost, here there is the solution I use when I need to initialize a static map:

typedef std::pair< int, char > elemPair_t;
elemPair_t elemPairs[] = 
{
    elemPair_t( 1, 'a'), 
    elemPair_t( 3, 'b' ), 
    elemPair_t( 5, 'c' ), 
    elemPair_t( 7, 'd' )
};

const std::map< int, char > myMap( &elemPairs[ 0 ], &elemPairs[ sizeof( elemPairs ) / sizeof( elemPairs[ 0 ] ) ] );

Make Frequency Histogram for Factor Variables

It seems like you want barplot(prop.table(table(animals))):

enter image description here

However, this is not a histogram.

An existing connection was forcibly closed by the remote host

I've got this exception because of circular reference in entity.In entity that look like

public class Catalog
{
    public int Id { get; set; }
    public int ParentId { get; set; }
    public Catalog Parent { get; set; }
    public ICollection<Catalog> ChildCatalogs { get; set; }
}

I added [IgnoreDataMemberAttribute] to the Parent property. And that solved the problem.

Comparing date part only without comparing time in JavaScript

You can use some arithmetic with the total of ms.

var date = new Date(date1);
date.setHours(0, 0, 0, 0);

var diff = date2.getTime() - date.getTime();
return diff >= 0 && diff < 86400000;

I like this because no updates to the original dates are made and perfom faster than string split and compare.

Hope this help!

How to create javascript delay function

Ah yes. Welcome to Asynchronous execution.

Basically, pausing a script would cause the browser and page to become unresponsive for 3 seconds. This is horrible for web apps, and so isn't supported.

Instead, you have to think "event-based". Use setTimeout to call a function after a certain amount of time, which will continue to run the JavaScript on the page during that time.

How do I install the ext-curl extension with PHP 7?

We can install any PHP7 Extensions which we are needed at the time of install Magento just use related command which you get error at the time of installin Magento

sudo apt-get install php7.0-curl
sudo apt-get install php7.0-dom
sudo apt-get install php7.0-mcrypt
sudo apt-get install php7.0-simplexml
sudo apt-get install php7.0-spl
sudo apt-get install php7.0-xsl
sudo apt-get install php7.0-intl
sudo apt-get install php7.0-mbstring
sudo apt-get install php7.0-ctype
sudo apt-get install php7.0-hash
sudo apt-get install php7.0-openssl
sudo apt-get install php7.0-zip
sudo apt-get install php7.0-xmlwriter
sudo apt-get install php7.0-gd
sudo apt-get install php7.0-iconv

Thanks! Hope this will help you

Hide axis and gridlines Highcharts

If you have bigger version than v4.9 of Highcharts you can use visible: false in the xAxis and yAxis settings.

Example:

$('#container').highcharts({

    chart: {
        type: 'column'
    },

    title: {
        text: 'Highcharts axis visibility'
    },

    xAxis: {
        visible: false
    },

    yAxis: {
        title: {
            text: 'Fruit'
        },
        visible: false
    }

});

How to read and write to a text file in C++?

Default c++ mechanism for file IO is called streams. Streams can be of three flavors: input, output and inputoutput. Input streams act like sources of data. To read data from an input stream you use >> operator:

istream >> my_variable; //This code will read a value from stream into your variable.

Operator >> acts different for different types. If in the example above my_variable was an int, then a number will be read from the strem, if my_variable was a string, then a word would be read, etc. You can read more then one value from the stream by writing istream >> a >> b >> c; where a, b and c would be your variables.

Output streams act like sink to which you can write your data. To write your data to a stream, use << operator.

ostream << my_variable; //This code will write a value from your variable into stream.

As with input streams, you can write several values to the stream by writing something like this:

ostream << a << b << c;

Obviously inputoutput streams can act as both.

In your code sample you use cout and cin stream objects. cout stands for console-output and cin for console-input. Those are predefined streams for interacting with default console.

To interact with files, you need to use ifstream and ofstream types. Similar to cin and cout, ifstream stands for input-file-stream and ofstream stands for output-file-stream.

Your code might look like this:

#include <iostream>
#include <fstream>

using namespace std;

int start()
{
    cout << "Welcome...";

    // do fancy stuff

    return 0;
}

int main ()
{
    string usreq, usr, yn, usrenter;

    cout << "Is this your first time using TEST" << endl;
    cin >> yn;
    if (yn == "y")
    {
        ifstream iusrfile;
        ofstream ousrfile;
        iusrfile.open("usrfile.txt");
        iusrfile >> usr;
        cout << iusrfile; // I'm not sure what are you trying to do here, perhaps print iusrfile contents?
        iusrfile.close();
        cout << "Please type your Username. \n";
        cin >> usrenter;
        if (usrenter == usr)
        {
            start ();
        }
    }
    else
    {
        cout << "THAT IS NOT A REGISTERED USERNAME.";
    }

    return 0;
}

For further reading you might want to look at c++ I/O reference

How can I generate Unix timestamps?

public static Int32 GetTimeStamp()
    {
        try
        {
            Int32 unixTimeStamp;
            DateTime currentTime = DateTime.Now;
            DateTime zuluTime = currentTime.ToUniversalTime();
            DateTime unixEpoch = new DateTime(1970, 1, 1);
            unixTimeStamp = (Int32)(zuluTime.Subtract(unixEpoch)).TotalSeconds;
            return unixTimeStamp;
        }
        catch (Exception ex)
        {
            Debug.WriteLine(ex);
            return 0;
        }
    }

There are No resources that can be added or removed from the server

I encountered this error even though the Project Facets were set appropriately. The problem was that the "Runtime Environment" property was not set on the server:

Empty Runtime Environment for Eclipse Tomcat

It simply needed to be set to the appropriate Runtime:

Runtime Environment for Eclipse Tomcat

How to create threads in nodejs

The nodejs 10.5.0 release has announced multithreading in Node.js. The feature is still experimental. There is a new worker_threads module available now.

You can start using worker threads if you run Node.js v10.5.0 or higher, but this is an experimental API. It is not available by default: you need to enable it by using --experimental-worker when invoking Node.js.

Here is an example with ES6 and worker_threads enabled, tested on version 12.3.1

//package.json

  "scripts": {
  "start": "node  --experimental-modules --experimental- worker index.mjs"
  },

Now, you need to import Worker from worker_threads. Note: You need to declare you js files with '.mjs' extension for ES6 support.

//index.mjs
import { Worker } from 'worker_threads';

const spawnWorker = workerData => {
    return new Promise((resolve, reject) => {
        const worker = new Worker('./workerService.mjs', { workerData });
        worker.on('message', resolve);
        worker.on('error', reject);
        worker.on('exit', code => code !== 0 && reject(new Error(`Worker stopped with 
        exit code ${code}`)));
    })
}

const spawnWorkers = () => {
    for (let t = 1; t <= 5; t++)
        spawnWorker('Hello').then(data => console.log(data));
}

spawnWorkers();

Finally, we create a workerService.mjs

//workerService.mjs
import { workerData, parentPort, threadId } from 'worker_threads';

// You can do any cpu intensive tasks here, in a synchronous way
// without blocking the "main thread"
parentPort.postMessage(`${workerData} from worker ${threadId}`);

Output:

npm run start

Hello from worker 4
Hello from worker 3
Hello from worker 1
Hello from worker 2
Hello from worker 5

How do I call a function inside of another function?

_x000D_
_x000D_
function function_one() {_x000D_
    function_two(); // considering the next alert, I figured you wanted to call function_two first_x000D_
    alert("The function called 'function_one' has been called.");_x000D_
}_x000D_
_x000D_
function function_two() {_x000D_
    alert("The function called 'function_two' has been called.");_x000D_
}_x000D_
_x000D_
function_one();
_x000D_
_x000D_
_x000D_

A little bit more context: this works in JavaScript because of a language feature called "variable hoisting" - basically, think of it like variable/function declarations are put at the top of the scope (more info).

How to echo out table rows from the db (php)

$sql = "SELECT * FROM YOUR_TABLE_NAME";
$result = mysqli_query($conn, $sql); // First parameter is just return of "mysqli_connect()" function
echo "<br>";
echo "<table border='1'>";
while ($row = mysqli_fetch_assoc($result)) { // Important line !!!
    echo "<tr>";
    foreach ($row as $field => $value) { // If you want you can right this line like this: foreach($row as $value) {
        echo "<td>" . $value . "</td>"; 
    }
    echo "</tr>";
}
echo "</table>";

In PHP 7.x You should use mysqli functions and most important one in while loop condition use "mysqli_fetch_assoc()" function not "mysqli_fetch_array()" one. If you would use "mysqli_fetch_array()", you will see your results are duplicated. Just try these two and see the difference.

Git copy changes from one branch to another

Copy content of BranchA into BranchB

git checkout BranchA
git pull origin BranchB
git push -u origin BranchA

Java, How to specify absolute value and square roots

import java.util.Scanner;
class my{
public static void main(String args[])
{
    Scanner x=new Scanner(System.in);
    double a,b,c=0,d;
    d=1;
    d=d/10;
    int e,z=0;
    System.out.print("Enter no:");
    a=x.nextInt();

    for(b=1;b<=a/2;b++)
    {
        if(b*b==a)
        {
            c=b;
            break;
        }
        else
        {
            if(b*b>a)
            break;
        }
    } 
    b--;
    if(c==0)
    {
       for(e=1;e<=15;e++)
        {
            while(b*b<=a && z==0)
            {
                if(b*b==a){c=b;z=1;}
                else
                {
                    b=b+d;          //*d==0.1 first time*//
                    if(b*b>=a){z=1;b=b-d;}
                }
            }
            d=d/10;
            z=0;
        }
        c=b;
    }

        System.out.println("Squre root="+c);





}    
}    

Can I use an image from my local file system as background in HTML?

FireFox does not allow to open a local file. But if you want to use this for testing a different image (which is what I just needed to do), you can simply save the whole page locally, and then insert the url(file:///somewhere/file.png) - which works for me.

How to run TestNG from command line

Below command works for me. Provided that all required jars including testng jar kept inside lib.

java -cp "lib/*" org.testng.TestNG testng.xml

Adding a new line/break tag in XML

The solution to this question is:

<?xml version="1.0" encoding="utf-8"?>
<?xml-stylesheet type="text/xsl" href="dummy.xsl"?>
  <item>
     <summary>
        <![CDATA[Tootsie roll tiramisu macaroon wafer carrot cake. <br />      
                 Danish topping sugar plum tart bonbon caramels cake.]]>
     </summary>
  </item>

by adding the <br /> inside the the <![CDATA]]> this allows the line to break, thus creating a new line!

How do I get a list of all the duplicate items using pandas in python?

Using an element-wise logical or and setting the take_last argument of the pandas duplicated method to both True and False you can obtain a set from your dataframe that includes all of the duplicates.

df_bigdata_duplicates = 
    df_bigdata[df_bigdata.duplicated(cols='ID', take_last=False) |
               df_bigdata.duplicated(cols='ID', take_last=True)
              ]

Using Default Arguments in a Function

<?php
function info($name="George",$age=18) {
echo "$name is $age years old.<br>";
}
info();     // prints default values(number of values = 2)
info("Nick");   // changes first default argument from George to Nick
info("Mark",17);    // changes both default arguments' values

?>

Change background color of selected item on a ListView

View updateview;// above oncreate method
listView.setChoiceMode(ListView.CHOICE_MODE_SINGLE);


listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
         if (updateview != null) 
            updateview.setBackgroundColor(Color.TRANSPARENT);
         updateview = view;   

         view.setBackgroundColor(Color.CYAN);
     }
});

Creating an index on a table variable

If Table variable has large data, then instead of table variable(@table) create temp table (#table).table variable doesn't allow to create index after insert.

 CREATE TABLE #Table(C1 int,       
  C2 NVarchar(100) , C3 varchar(100)
  UNIQUE CLUSTERED (c1) 
 ); 
  1. Create table with unique clustered index

  2. Insert data into Temp "#Table" table

  3. Create non clustered indexes.

     CREATE NONCLUSTERED INDEX IX1  ON #Table (C2,C3);
    

How to allow only numbers in textbox in mvc4 razor

Maybe you can use the [Integer] data annotation (If you use the DataAnnotationsExtensions http://dataannotationsextensions.org/) . However, this wil only check if the value is an integer, nót if it is filled in (So you may also need the [Required] attribute).

If you enable Unobtrusive Validation it will validate it clientside, but you should also use Modelstate.Valid in your POST action to decline it in case people have Javascript disabled.

OpenSSL and error in reading openssl.conf file

The problem here is that there ISN'T an openssl.cnf file given with the GnuWin32 openssl stuff. You have to create it. You can find out HOW to create an openssl.cnf file by going here:

http://www.flatmtn.com/article/setting-ssl-certificates-apache

Where it lays it all out for you on how to do it.

PLEASE NOTE: The openssl command given with the backslash at the end is for UNIX. For Windows : 1)Remove the backslash, and 2)Move the second line up so it is at the end of the first line. (So you get just one command.)

ALSO: It is VERY important to read through the comments. There are some changes you might want to make based upon them.

android: how to change layout on button click?

It is very simple, just do this:

t4.setOnClickListener(new OnClickListener(){

        @Override
        public void onClick(View v) {

            launchQuiz2();          // TODO Auto-generated method stub

        }

        private void launchQuiz2() {
            Intent i = new Intent(MainActivity.this, Quiz2.class);
            startActivity(i);
            // TODO Auto-generated method stub

        }

    });

How to calculate sum of a formula field in crystal Reports?

You can try like this:

Sum({Tablename.Columnname})

It will work without creating a summarize field in formulae.

Retrieve specific commit from a remote Git repository

Finally i found a way to clone specific commit using git cherry-pick. Assuming you don't have any repository in local and you are pulling specific commit from remote,

1) create empty repository in local and git init

2) git remote add origin "url-of-repository"

3) git fetch origin [this will not move your files to your local workspace unless you merge]

4) git cherry-pick "Enter-long-commit-hash-that-you-need"

Done.This way, you will only have the files from that specific commit in your local.

Enter-long-commit-hash:

You can get this using -> git log --pretty=oneline

How to enable and use HTTP PUT and DELETE with Apache2 and PHP?

You don't need to configure anything. Just make sure that the requests map to your PHP file and use requests with path info. For example, if you have in the root a file named handler.php with this content:

<?php

var_dump($_SERVER['REQUEST_METHOD']);
var_dump($_SERVER['REQUEST_URI']);
var_dump($_SERVER['PATH_INFO']);

if (($stream = fopen('php://input', "r")) !== FALSE)
    var_dump(stream_get_contents($stream));

The following HTTP request would work:

Established connection with 127.0.0.1 on port 81
PUT /handler.php/bla/foo HTTP/1.1
Host: localhost:81
Content-length: 5
 
boo
HTTP/1.1 200 OK
Date: Sat, 29 May 2010 16:00:20 GMT
Server: Apache/2.2.13 (Win32) PHP/5.3.0
X-Powered-By: PHP/5.3.0
Content-Length: 89
Content-Type: text/html
 
string(3) "PUT"
string(20) "/handler.php/bla/foo"
string(8) "/bla/foo"
string(5) "boo
"
Connection closed remotely.

You can hide the "php" extension with MultiViews or you can make URLs completely logical with mod_rewrite.

See also the documentation for the AcceptPathInfo directive and this question on how to make PHP not parse POST data when enctype is multipart/form-data.

Could not load file or assembly or one of its dependencies. Access is denied. The issue is random, but after it happens once, it continues

If you are using impersonation, be sure to give permissions, including write and modify permission to the relevant user account on the following folder:

C:\Users\[username]\AppData\Local\Temp\Temporary ASP.NET Files

I was missing the modify permission, which was why just adding the default permissions wasn't working for me.

How to get the squared symbol (²) to display in a string

I create equations with random numbers in VBA and for x squared put in x^2.

I read each square (or textbox) text into a string.

I then read each character in the string in turn and note the location of the ^ ("hats")'s in each.

Say the hats were at positions 4, 8 and 12.

I then "chop out" the first hat - the position of the character to be superscripted is now 4, the position of the other hats is now 7 and 11. I chop out the second hat, the character to superscript is now at 7 and the hat has moved to 10. I chop out the last hat .. the superscript character is now position 10.

I now select each character in turn and change the font to superscript.

Thus I can fill a whole spreadsheet with algebra using ^ and then call a routine to tidy it up.

For big powers like x to the 23 I build x^2^3 and the above routine does it.

Deny access to one specific folder in .htaccess

Create site/includes/.htaccess file and add this line:

Deny from all

Python: Continuing to next iteration in outer loop

I think one of the easiest ways to achieve this is to replace "continue" with "break" statement,i.e.

for ii in range(200):
 for jj in range(200, 400):
    ...block0...
    if something:
        break
 ...block1...       

For example, here is the easy code to see how exactly it goes on:

for i in range(10):
    print("doing outer loop")
    print("i=",i)
    for p in range(10):
        print("doing inner loop")
        print("p=",p)
        if p==3:
            print("breaking from inner loop")
            break
    print("doing some code in outer loop")

How to sort an array in Bash

sorted=($(echo ${array[@]} | tr " " "\n" | sort))

In the spirit of bash / linux, I would pipe the best command-line tool for each step. sort does the main job but needs input separated by newline instead of space, so the very simple pipeline above simply does:

Echo array content --> replace space by newline --> sort

$() is to echo the result

($()) is to put the "echoed result" in an array

Note: as @sorontar mentioned in a comment to a different question:

The sorted=($(...)) part is using the "split and glob" operator. You should turn glob off: set -f or set -o noglob or shopt -op noglob or an element of the array like * will be expanded to a list of files.

In Java, how do I call a base class's method from the overriding method in a derived class?

See, here you are overriding one of the method of the base class hence if you like to call base class method from inherited class then you have to use super keyword in the same method of the inherited class.

Create JPA EntityManager without persistence.xml configuration file

Yes you can without using any xml file using spring like this inside a @Configuration class (or its equivalent spring config xml):

@Bean
public LocalContainerEntityManagerFactoryBean emf(){
    properties.put("javax.persistence.jdbc.driver", dbDriverClassName);
    properties.put("javax.persistence.jdbc.url", dbConnectionURL);
    properties.put("javax.persistence.jdbc.user", dbUser); //if needed

    LocalContainerEntityManagerFactoryBean emf = new LocalContainerEntityManagerFactoryBean();
    emf.setPersistenceProviderClass(org.eclipse.persistence.jpa.PersistenceProvider.class); //If your using eclipse or change it to whatever you're using
    emf.setPackagesToScan("com.yourpkg"); //The packages to search for Entities, line required to avoid looking into the persistence.xml
    emf.setPersistenceUnitName(SysConstants.SysConfigPU);
    emf.setJpaPropertyMap(properties);
    emf.setLoadTimeWeaver(new ReflectiveLoadTimeWeaver()); //required unless you know what your doing
    return emf;
}

Function for C++ struct

Structs can have functions just like classes. The only difference is that they are public by default:

struct A {
    void f() {}
};

Additionally, structs can also have constructors and destructors.

struct A {
    A() : x(5) {}
    ~A() {}

    private: int x;
};

Convert Json String to C# Object List

Try to change type of ScoreIfNoMatch, like this:

   public class MatrixModel
        {
            public string S1 { get; set; }
            public string S2 { get; set; }
            public string S3 { get; set; }
            public string S4 { get; set; }
            public string S5 { get; set; }
            public string S6 { get; set; }
            public string S7 { get; set; }
            public string S8 { get; set; }
            public string S9 { get; set; }
            public string S10 { get; set; }
            // the type should be string
            public string ScoreIfNoMatch { get; set; }
        }

How to find rows in one table that have no corresponding row in another table

select tableA.id from tableA left outer join tableB on (tableA.id = tableB.id)
where tableB.id is null
order by tableA.id desc 

If your db knows how to do index intersections, this will only touch the primary key index

IIS error, Unable to start debugging on the webserver

Just to add in my 2 cents.

Recently I installed docker for another project and this was causing a project running on IIS Express to generate the error “The specified port is in use”. To solve this I did a few things, but namely I executed this command:

netsh http add iplisten ipaddress=::

This commands breaks down sites running on IIS Local, so if you executed this command you can make your IIS Local sites working again by executing the following which undoes the previous command:

netsh http delete iplisten ipaddress=::

How to center a subview of UIView

With IOS9 you can use the layout anchor API.

The code would look like this:

childview.centerXAnchor.constraintEqualToAnchor(parentView.centerXAnchor).active = true
childview.centerYAnchor.constraintEqualToAnchor(parentView.centerYAnchor).active = true

The advantage of this over CGPointMake or CGRect is that with those methods you are setting the center of the view to a constant but with this technique you are setting a relationship between the two views that will hold forever, no matter how the parentview changes.

Just be sure before you do this to do:

        self.view.addSubview(parentView)
        self.view.addSubView(chidview)

and to set the translatesAutoresizingMaskIntoConstraints for each view to false.

This will prevent crashing and AutoLayout from interfering.

How to display PDF file in HTML?

If you want to use pdf.js, I suggest you to read THIS

You can also upload your pdf somewhere (like Google Drive) and use its URL in a iframe

or

<object data="data/test.pdf" type="application/pdf" width="300" height="200">
<a href="data/test.pdf">test.pdf</a>
</object>

What is the difference between a static method and a non-static method?

Well, more technically speaking, the difference between a static method and a virtual method is the way the are linked.

A traditional "static" method like in most non OO languages gets linked/wired "statically" to its implementation at compile time. That is, if you call method Y() in program A, and link your program A with library X that implements Y(), the address of X.Y() is hardcoded to A, and you can not change that.

In OO languages like JAVA, "virtual" methods are resolved "late", at run-time, and you need to provide an instance of a class. So in, program A, to call virtual method Y(), you need to provide an instance, B.Y() for example. At runtime, every time A calls B.Y() the implementation called will depend on the instance used, so B.Y() , C.Y() etc... could all potential provide different implementations of Y() at runtime.

Why will you ever need that? Because that way you can decouple your code from the dependencies. For example, say program A is doing "draw()". With a static language, thats it, but with OO you will do B.draw() and the actual drawing will depend on the type of object B, which, at runtime, can change to square a circle etc. That way your code can draw multiple things with no need to change, even if new types of B are provided AFTER the code was written. Nifty -

How to use Checkbox inside Select Option

For a Pure CSS approach, you can use the :checked selector combined with the ::before selector to inline conditional content.

Just add the class select-checkbox to your select element and include the following CSS:

.select-checkbox option::before {
  content: "\2610";
  width: 1.3em;
  text-align: center;
  display: inline-block;
}
.select-checkbox option:checked::before {
  content: "\2611";
}

You can use plain old unicode characters (with an escaped hex encoding) like these:

Or if you want to spice things up, you can use these FontAwesome glyphs

Screenshot

Demo in jsFiddle & Stack Snippets

_x000D_
_x000D_
select {_x000D_
  width: 150px;_x000D_
}_x000D_
_x000D_
.select-checkbox option::before {_x000D_
  content: "\2610";_x000D_
  width: 1.3em;_x000D_
  text-align: center;_x000D_
  display: inline-block;_x000D_
}_x000D_
.select-checkbox option:checked::before {_x000D_
  content: "\2611";_x000D_
}_x000D_
_x000D_
.select-checkbox-fa option::before {_x000D_
  font-family: FontAwesome;_x000D_
  content: "\f096";_x000D_
  width: 1.3em;_x000D_
  display: inline-block;_x000D_
  margin-left: 2px;_x000D_
}_x000D_
.select-checkbox-fa option:checked::before {_x000D_
  content: "\f046";_x000D_
}
_x000D_
<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.css">_x000D_
_x000D_
<h3>Unicode</h3>_x000D_
<select multiple="" class="form-control select-checkbox" size="5">_x000D_
  <option>Dog</option>_x000D_
  <option>Cat</option>_x000D_
  <option>Hippo</option>_x000D_
  <option>Dinosaur</option>_x000D_
  <option>Another Dog</option>_x000D_
</select>_x000D_
_x000D_
<h3>Font Awesome</h3>_x000D_
<select multiple="" class="form-control select-checkbox-fa" size="5">_x000D_
  <option>Dog</option>_x000D_
  <option>Cat</option>_x000D_
  <option>Hippo</option>_x000D_
  <option>Dinosaur</option>_x000D_
  <option>Another Dog</option>_x000D_
</select>
_x000D_
_x000D_
_x000D_

Note: Beware of IE compatibility issues however

Getting text from td cells with jQuery

I would give your tds a specific class, e.g. data-cell, and then use something like this:

$("td.data-cell").each(function () {
    // 'this' is now the raw td DOM element
    var txt = $(this).html();
});

Why does using an Underscore character in a LIKE filter give me all the results?

You can write the query as below:

SELECT * FROM Manager
WHERE managerid LIKE '\_%' escape '\'
AND managername LIKE '%\_%' escape '\';

it will solve your problem.

Printing 1 to 1000 without loop or conditionals

It's also possible to do it with plain dynamic dispatch (works in Java too):

#include<iostream>
using namespace std;

class U {
  public:
  virtual U* a(U* x) = 0; 
  virtual void p(int i) = 0;
  static U* t(U* x) { return x->a(x->a(x->a(x))); }
};

class S : public U {
  public:
  U* h;
  S(U* h) : h(h) {}
  virtual U* a(U* x) { return new S(new S(new S(h->a(x)))); }
  virtual void p(int i) { cout << i << endl; h->p(i+1); }
};

class Z : public U {
  public:
  virtual U* a(U* x) { return x; }
  virtual void p(int i) {}
};

int main(int argc, char** argv) {
  U::t(U::t(U::t(new S(new Z()))))->p(1);
}

MySQL "CREATE TABLE IF NOT EXISTS" -> Error 1050

Well there are lot of answeres already provided and lot are making sense too.

Some mentioned it is just warning and some giving a temp way to disable warnings. All that will work but add risk when number of transactions in your DB is high.

I came across similar situation today and here is the query I came up with...

declare
begin
  execute immediate '
    create table "TBL" ("ID" number not null)';
  exception when others then
    if SQLCODE = -955 then null; else raise; end if;
end;
/

This is simple, if exception come while running query it will be suppressed. and you can use same for SQL or Oracle.

What does it mean to "program to an interface"?

To add to the existing posts, sometimes coding to interfaces helps on large projects when developers work on separate components simultaneously. All you need is to define interfaces upfront and write code to them while other developers write code to the interface you are implementing.

Ignore files that have already been committed to a Git repository

To untrack a file that has already been added/initialized to your repository, ie stop tracking the file but not delete it from your system use: git rm --cached filename

Gson: How to exclude specific fields from Serialization without annotations

I used this strategy: i excluded every field which is not marked with @SerializedName annotation, i.e.:

public class Dummy {

    @SerializedName("VisibleValue")
    final String visibleValue;
    final String hiddenValue;

    public Dummy(String visibleValue, String hiddenValue) {
        this.visibleValue = visibleValue;
        this.hiddenValue = hiddenValue;
    }
}


public class SerializedNameOnlyStrategy implements ExclusionStrategy {

    @Override
    public boolean shouldSkipField(FieldAttributes f) {
        return f.getAnnotation(SerializedName.class) == null;
    }

    @Override
    public boolean shouldSkipClass(Class<?> clazz) {
        return false;
    }
}


Gson gson = new GsonBuilder()
                .setExclusionStrategies(new SerializedNameOnlyStrategy())
                .create();

Dummy dummy = new Dummy("I will see this","I will not see this");
String json = gson.toJson(dummy);

It returns

{"VisibleValue":"I will see this"}

EC2 Instance Cloning

To Answer your question: now AWS make cloning real easy see Launch instance from your Existing Instance

  1. On the EC2 Instances page, select the instance you want to use
  2. Choose Actions, and then Launch More Like This.
  3. Review & Launch

This will take the existing instance as a Template for the new once.

or you can also take a snapshot of the existing volume and use the snapshot with the AMI (existing one) which you ping during your instance launch

How to convert a string variable containing time to time_t type in c++?

This should work:

int hh, mm, ss;
struct tm when = {0};

sscanf_s(date, "%d:%d:%d", &hh, &mm, &ss);


when.tm_hour = hh;
when.tm_min = mm;
when.tm_sec = ss;

time_t converted;
converted = mktime(&when);

Modify as needed.

Could not create the Java virtual machine

Make sure the physical available memory is more then VM defined min/max memory.

How to check if a String contains only ASCII?

commons-lang3 from Apache contains valuable utility/convenience methods for all kinds of 'problems', including this one.

System.out.println(StringUtils.isAsciiPrintable("!@£$%^&!@£$%^"));

Detect HTTP or HTTPS then force HTTPS in JavaScript

Functional way

window.location.protocol === 'http:' && (location.href = location.href.replace(/^http:/, 'https:'));

What is the meaning of prepended double colon "::"?

The :: operator is called the scope-resolution operator and does just that, it resolves scope. So, by prefixing a type-name with this, it tells your compiler to look in the global namespace for the type.

Example:

int count = 0;

int main(void) {
  int count = 0;
  ::count = 1;  // set global count to 1
  count = 2;    // set local count to 2
  return 0;
}

How can I compare two ordered lists in python?

Just use the classic == operator:

>>> [0,1,2] == [0,1,2]
True
>>> [0,1,2] == [0,2,1]
False
>>> [0,1] == [0,1,2]
False

Lists are equal if elements at the same index are equal. Ordering is taken into account then.

How to use makefiles in Visual Studio?

A UNIX guy probably told you that. :)

You can use makefiles in VS, but when you do it bypasses all the built-in functionality in MSVC's IDE. Makefiles are basically the reinterpret_cast of the builder. IMO the simplest thing is just to use Solutions.

Remove and Replace Printed items

Just use CR to go to beginning of the line.

import time
for x in range (0,5):  
    b = "Loading" + "." * x
    print (b, end="\r")
    time.sleep(1)

Datatable select with multiple conditions

Try this,
I think ,this is one of the simple solutions.

int rowIndex = table.Rows.IndexOf(table.Select("A = 'foo' AND B = 'bar' AND C = 'baz'")[0]);
string strD= Convert.ToString(table.Rows[rowIndex]["D"]);

Make sure,combination of values for column A, B and C is unique in the datatable.

Show div #id on click with jQuery

This is simple way to Display Div using:-

$("#musicinfo").show();  //or
$("#musicinfo").css({'display':'block'});  //or
$("#musicinfo").toggle("slow");   //or
$("#musicinfo").fadeToggle();    //or

How do I add options to a DropDownList using jQuery?

With the plugin: jQuery Selection Box. You can do this:

var myOptions = {
        "Value 1" : "Text 1",
        "Value 2" : "Text 2",
        "Value 3" : "Text 3"
    }
    $("#myselect2").addOption(myOptions, false); 

How To Create Table with Identity Column

[id] [int] IDENTITY(1,1) NOT NULL,

of course since you're creating the table in SQL Server Management Studio you could use the table designer to set the Identity Specification.

enter image description here

Raise to power in R

1: No difference. It is kept around to allow old S-code to continue to function. This is documented a "Note" in ?Math

2: Yes: But you already know it:

`^`(x,y)
#[1] 1024

In R the mathematical operators are really functions that the parser takes care of rearranging arguments and function names for you to simulate ordinary mathematical infix notation. Also documented at ?Math.

Edit: Let me add that knowing how R handles infix operators (i.e. two argument functions) is very important in understanding the use of the foundational infix "[[" and "["-functions as (functional) second arguments to lapply and sapply:

> sapply( list( list(1,2,3), list(4,3,6) ), "[[", 1)
[1] 1 4
> firsts <- function(lis) sapply(lis, "[[", 1)
> firsts( list( list(1,2,3), list(4,3,6) ) )
[1] 1 4

Write single CSV file using spark-csv

I'm using this in Python to get a single file:

df.toPandas().to_csv("/tmp/my.csv", sep=',', header=True, index=False)

How to edit incorrect commit message in Mercurial?

Good news: hg 2.2 just added git like --amend option.

and in tortoiseHg, you can use "Amend current revision" by select black arrow on the right of commit button

a

HTML table with horizontal scrolling (first column fixed)

Use jQuery DataTables plug-in, it supports fixed header and columns. This example adds fixed column support to the html table "example":

http://datatables.net/extensions/fixedcolumns/

For two fixed columns:

http://www.datatables.net/release-datatables/extensions/FixedColumns/examples/two_columns.html

How to reset or change the passphrase for a GitHub SSH key?

Passphrases can be added to an existing key or changed without regenerating the key pair:
Note This will work if keys doesn't had a passphrase, otherwise you'll get this: Enter old passphrase: then Bad passphrase

$ ssh-keygen -p
Enter file in which the key is (/Users/tekkub/.ssh/id_rsa):
Key has comment '/Users/tekkub/.ssh/id_rsa'
Enter new passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved with the new passphrase.

If your key had passphrase then, There's no way to recover the passphrase for a pair of SSH keys. In that case you have to create a new pair of SSH keys.

  1. Generating SSH keys

How to change the author and committer name and e-mail of multiple commits in Git?

Github has a nice solution, which is the following shell script:

#!/bin/sh

git filter-branch --env-filter '

an="$GIT_AUTHOR_NAME"
am="$GIT_AUTHOR_EMAIL"
cn="$GIT_COMMITTER_NAME"
cm="$GIT_COMMITTER_EMAIL"

if [ "$GIT_COMMITTER_EMAIL" = "[email protected]" ]
then
    cn="Your New Committer Name"
    cm="Your New Committer Email"
fi
if [ "$GIT_AUTHOR_EMAIL" = "[email protected]" ]
then
    an="Your New Author Name"
    am="Your New Author Email"
fi

export GIT_AUTHOR_NAME="$an"
export GIT_AUTHOR_EMAIL="$am"
export GIT_COMMITTER_NAME="$cn"
export GIT_COMMITTER_EMAIL="$cm"
'

Simulate low network connectivity for Android

Facebook built something called Augmented Traffic Control. A brief summary from their GitHub page:

Augmented Traffic Control (ATC) is a tool to simulate network conditions. It allows controlling the connection that a device has to the internet. Developers can use ATC to test their application across varying network conditions, easily emulating high speed, mobile, and even severely impaired networks. Aspects of the connection that can be controlled include:

  • bandwidth
  • latency
  • packet loss
  • corrupted packets
  • packets ordering

In order to be able to shape the network traffic, ATC must be running on a device that routes the traffic and sees the real IP address of the device, like your network gateway for instance. This also allows any devices that route through ATC to be able to shape their traffic. Traffic can be shaped/unshaped using a web interface allowing any devices with a web browser to use ATC without the need for a client application.

You can find it here on GitHub: https://github.com/facebook/augmented-traffic-control

They have also written a blog post about it: https://code.facebook.com/posts/1561127100804165/augmented-traffic-control-a-tool-to-simulate-network-conditions/

How to tell which disk Windows Used to Boot

  1. Go into Control Panel
  2. System and Security
  3. Administrative Tools
  4. Launch the System Configuration tool

If you have multiple copies of Windows installed, the one you are booted with will be named such as:

Windows 7 (F:\Windows)
Windows 7 (C:\Windows) : Current OS, Default OS

Jenkins could not run git

Like Darksaint2014 said, you need to configure two parts if you installed Jenkins in Windows.

If you installed your Jenkins in windows, you need to install Git in both local and your linux server, then configure below in both locations:


Global tool configuration:

global tool configuration


For server side:

For server side


How do I find and replace all occurrences (in all files) in Visual Studio Code?

I'm using Visual Studio Code 1.8, and this feature is available. But it's a little tricky to understand at first, and (at the time of writing) the docs don't explain clearly how to use it, so here's how it works, step by step:

Invoke Replace in Files (under the Edit menu, or with shortcut Ctrl+Shift+H)

You'll see a standard Find/Replace input replacing the files pane on the left:

enter image description here

Enter your search string and the replace string, then press enter. It may churn for a second searching all files, then it'll show the proposed changes in all your project files -- but note, these changes haven't been made yet! Here's what it looks like:

enter image description here

Now you need to make the changes (and even after that, you have to save the modified files.)

You can make those changes in various ways:

1) Make all changes to all files at once.

Click the replace icon next to your replace string (note: you'll get a dialog to confirm this bulk action.)

enter image description here

2) Make all changes in a single file at once.

Click the replace icon next to the filename (note: the icon only shows up when you hover over the filename row)

enter image description here

3) Make a single change in a single file.

Click the replace icon next to the individual change: (note: the icon only shows up when you hover over the change row)

enter image description here

Finally, don't forget to save!

All those files are now modified in the editor and not yet saved to disk.

Use File -> Save All (or Ctrl+Alt+S)

Update: I'm not sure when this was added, but if you click the "Replace all" button and see this dialog, clicking "Replace" will change and save all files in one click:

enter image description here

'uint32_t' identifier not found error

On Windows I usually use windows types. To use it you have to include <Windows.h>.

In this case uint32_t is UINT32 or just UINT.

All types definitions are here: http://msdn.microsoft.com/en-us/library/windows/desktop/aa383751%28v=vs.85%29.aspx

Clearing the terminal screen?

the best way I can think of is using processing there are a few introductions on the net like displaying serial data, arduino graph and arduino radar
Since Arduino is based on processing its not that hard to learn

Regular expression to remove HTML tags from a string

You should not attempt to parse HTML with regex. HTML is not a regular language, so any regex you come up with will likely fail on some esoteric edge case. Please refer to the seminal answer to this question for specifics. While mostly formatted as a joke, it makes a very good point.


The following examples are Java, but the regex will be similar -- if not identical -- for other languages.


String target = someString.replaceAll("<[^>]*>", "");

Assuming your non-html does not contain any < or > and that your input string is correctly structured.

If you know they're a specific tag -- for example you know the text contains only <td> tags, you could do something like this:

String target = someString.replaceAll("(?i)<td[^>]*>", "");

Edit: Omega brought up a good point in a comment on another post that this would result in multiple results all being squished together if there were multiple tags.

For example, if the input string were <td>Something</td><td>Another Thing</td>, then the above would result in SomethingAnother Thing.

In a situation where multiple tags are expected, we could do something like:

String target = someString.replaceAll("(?i)<td[^>]*>", " ").replaceAll("\\s+", " ").trim();

This replaces the HTML with a single space, then collapses whitespace, and then trims any on the ends.

Good way of getting the user's location in Android

To select the right location provider for your app, you can use Criteria objects:

Criteria myCriteria = new Criteria();
myCriteria.setAccuracy(Criteria.ACCURACY_HIGH);
myCriteria.setPowerRequirement(Criteria.POWER_LOW);
// let Android select the right location provider for you
String myProvider = locationManager.getBestProvider(myCriteria, true); 

// finally require updates at -at least- the desired rate
long minTimeMillis = 600000; // 600,000 milliseconds make 10 minutes
locationManager.requestLocationUpdates(myProvider,minTimeMillis,0,locationListener); 

Read the documentation for requestLocationUpdates for more details on how the arguments are taken into account:

The frequency of notification may be controlled using the minTime and minDistance parameters. If minTime is greater than 0, the LocationManager could potentially rest for minTime milliseconds between location updates to conserve power. If minDistance is greater than 0, a location will only be broadcasted if the device moves by minDistance meters. To obtain notifications as frequently as possible, set both parameters to 0.

More thoughts

  • You can monitor the accuracy of the Location objects with Location.getAccuracy(), which returns the estimated accuracy of the position in meters.
  • the Criteria.ACCURACY_HIGH criterion should give you errors below 100m, which is not as good as GPS can be, but matches your needs.
  • You also need to monitor the status of your location provider, and switch to another provider if it gets unavailable or disabled by the user.
  • The passive provider may also be a good match for this kind of application: the idea is to use location updates whenever they are requested by another app and broadcast systemwide.

Why is "using namespace std;" considered bad practice?

Using many namespaces at the same time is obviously a recipe for disaster, but using JUST namespace std and only namespace std is not that big of a deal in my opinion because redefinition can only occur by your own code...

So just consider them functions as reserved names like "int" or "class" and that is it.

People should stop being so anal about it. Your teacher was right all along. Just use ONE namespace; that is the whole point of using namespaces the first place. You are not supposed to use more than one at the same time. Unless it is your own. So again, redefinition will not happen.

Windows batch script to unhide files hidden by virus

Try this one. Hope this is working fine.. :)

@ECHO off

cls

ECHO.

set drvltr=

set /p drvltr=Enter Drive letter: 

attrib -s -h -a /s /d  %drvltr%:\*.*

ECHO Unhide Completed

pause

Filename timestamp in Windows CMD batch script getting truncated

Windows batch log file name in 2018-02-08_14.32.06.34.log format:

setlocal
set d=%DATE:~-4%-%DATE:~4,2%-%DATE:~7,2%
set t=%time::=.% 
set t=%t: =%
set logfile="%d%_%t%.log"

ping localhost -n 11>%1/%logfile%
endlocal

What is "with (nolock)" in SQL Server?

Simple answer - whenever your SQL is not altering data, and you have a query that might interfere with other activity (via locking).

It's worth considering for any queries used for reports, especially if the query takes more than, say, 1 second.

It's especially useful if you have OLAP-type reports you're running against an OLTP database.

The first question to ask, though, is "why am I worrying about this?" ln my experience, fudging the default locking behavior often takes place when someone is in "try anything" mode and this is one case where unexpected consequences are not unlikely. Too often it's a case of premature optimization and can too easily get left embedded in an application "just in case." It's important to understand why you're doing it, what problem it solves, and whether you actually have the problem.

What is the difference between ndarray and array in numpy?

numpy.ndarray() is a class, while numpy.array() is a method / function to create ndarray.

In numpy docs if you want to create an array from ndarray class you can do it with 2 ways as quoted:

1- using array(), zeros() or empty() methods: Arrays should be constructed using array, zeros or empty (refer to the See Also section below). The parameters given here refer to a low-level method (ndarray(…)) for instantiating an array.

2- from ndarray class directly: There are two modes of creating an array using __new__: If buffer is None, then only shape, dtype, and order are used. If buffer is an object exposing the buffer interface, then all keywords are interpreted.

The example below gives a random array because we didn't assign buffer value:

np.ndarray(shape=(2,2), dtype=float, order='F', buffer=None)

array([[ -1.13698227e+002,   4.25087011e-303],
       [  2.88528414e-306,   3.27025015e-309]])         #random

another example is to assign array object to the buffer example:

>>> np.ndarray((2,), buffer=np.array([1,2,3]),
...            offset=np.int_().itemsize,
...            dtype=int) # offset = 1*itemsize, i.e. skip first element
array([2, 3])

from above example we notice that we can't assign a list to "buffer" and we had to use numpy.array() to return ndarray object for the buffer

Conclusion: use numpy.array() if you want to make a numpy.ndarray() object"

Python - abs vs fabs

Edit: as @aix suggested, a better (more fair) way to compare the speed difference:

In [1]: %timeit abs(5)
10000000 loops, best of 3: 86.5 ns per loop

In [2]: from math import fabs

In [3]: %timeit fabs(5)
10000000 loops, best of 3: 115 ns per loop

In [4]: %timeit abs(-5)
10000000 loops, best of 3: 88.3 ns per loop

In [5]: %timeit fabs(-5)
10000000 loops, best of 3: 114 ns per loop

In [6]: %timeit abs(5.0)
10000000 loops, best of 3: 92.5 ns per loop

In [7]: %timeit fabs(5.0)
10000000 loops, best of 3: 93.2 ns per loop

In [8]: %timeit abs(-5.0)
10000000 loops, best of 3: 91.8 ns per loop

In [9]: %timeit fabs(-5.0)
10000000 loops, best of 3: 91 ns per loop

So it seems abs() only has slight speed advantage over fabs() for integers. For floats, abs() and fabs() demonstrate similar speed.


In addition to what @aix has said, one more thing to consider is the speed difference:

In [1]: %timeit abs(-5)
10000000 loops, best of 3: 102 ns per loop

In [2]: import math

In [3]: %timeit math.fabs(-5)
10000000 loops, best of 3: 194 ns per loop

So abs() is faster than math.fabs().

What is better, adjacency lists or adjacency matrices for graph problems in C++?

Okay, I've compiled the Time and Space complexities of basic operations on graphs.
The image below should be self-explanatory.
Notice how Adjacency Matrix is preferable when we expect the graph to be dense, and how Adjacency List is preferable when we expect the graph to be sparse.
I've made some assumptions. Ask me if a complexity (Time or Space) needs clarification. (For example, For a sparse graph, I've taken En to be a small constant, as I've assumed that addition of a new vertex will add only a few edges, because we expect the graph to remain sparse even after adding that vertex.)

Please tell me if there are any mistakes.

enter image description here

Which is faster: Stack allocation or Heap allocation

An interesting thing I learned about Stack vs. Heap Allocation on the Xbox 360 Xenon processor, which may also apply to other multicore systems, is that allocating on the Heap causes a Critical Section to be entered to halt all other cores so that the alloc doesn't conflict. Thus, in a tight loop, Stack Allocation was the way to go for fixed sized arrays as it prevented stalls.

This may be another speedup to consider if you're coding for multicore/multiproc, in that your stack allocation will only be viewable by the core running your scoped function, and that will not affect any other cores/CPUs.

How can I display two div in one line via css inline property

use inline-block instead of inline. Read more information here about the difference between inline and inline-block.

.inline { 
display: inline-block; 
border: 1px solid red; 
margin:10px;
}

DEMO

Can I disable a CSS :hover effect via JavaScript?

I would use CSS to prevent the :hover event from changing the appearance of the link.

a{
  font:normal 12px/15px arial,verdana,sans-serif;
  color:#000;
  text-decoration:none;
}

This simple CSS means that the links will always be black and not underlined. I cannot tell from the question whether the change in the appearance is the only thing you want to control.

How to remove a row from JTable?

The correct way to apply a filter to a JTable is through the RowFilter interface added to a TableRowSorter. Using this interface, the view of a model can be changed without changing the underlying model. This strategy preserves the Model-View-Controller paradigm, whereas removing the rows you wish hidden from the model itself breaks the paradigm by confusing your separation of concerns.

How can I get an object's absolute position on the page in Javascript?

var cumulativeOffset = function(element) {
    var top = 0, left = 0;
    do {
        top += element.offsetTop  || 0;
        left += element.offsetLeft || 0;
        element = element.offsetParent;
    } while(element);

    return {
        top: top,
        left: left
    };
};

(Method shamelessly stolen from PrototypeJS; code style, variable names and return value changed to protect the innocent)

How to solve "Unresolved inclusion: <iostream>" in a C++ file in Eclipse CDT?

I'd had this issue with Eclipse 2019-12 where the includes were previously being resolved, but then weren't. This was with a Meson build C/C++ project. I'm not sure exactly what happened, but closing the project and reopening it resolved the issue for me.